Tutorial

Basic Router Operation

by Shirley Myers, Marc R. Menninger, and Barry Meinster

Introduction for This Edition

The underlying structure of Cisco routers has undergone only minor changes since this Basic Router Operation document was last reviewed. This edition updates the material to reflect the new CCNA exam requirements and the router platforms that Cisco currently offers. Due to the vast quantity of affordable used or refurbished 2500 routers available on the Internet, the Cisco 2500 is still the primary platform that individuals wanting to get their CCNA certification use to get their initial hands-on exposure to Cisco routers. Some of the original document's configuration examples referenced the 2500 series routers and have been retained, some have been replaced with output from 2600 routers, and some newer 2600 output has been added to show the small differences between the configuration of newer versus older platforms.

Introduction

Today Cisco Systems has become the world's foremost developer and manufacturer of internetworking equipment and software. Cisco develops and manufactures over 80% of the routing equipment that controls the flows of information traveling on the Internet and private internetworks.

With this market dominance comes a huge demand for engineers and administrators that understand Cisco's routers and other products. One way that you can demonstrate understanding of Cisco routers and internetworking fundamentals is to pass the Cisco Certified Network Associate (CCNA) exam 640-801. The exam is broken into four main areas:

• Planning and Designing

• Implementation and Operation

• Troubleshooting

• Technology

You can find these topic areas at http://www.cisco.com/warp/public/10/wwtraining/certprog/testing/current_exams/640-801.html (CertificationZone is not associated with Cisco.)

If you prefer, you could obtain the CCNA certification by taking two exams instead: INTRO 640-821 (Introduction to Cisco Networking Technologies) exam and ICND 640-811 (Interconnecting Cisco Networking Devices). See http://www.cisco.com/warp/public/10/wwtraining/certprog/testing/current_exams/640-821.html and http://www.cisco.com/warp/public/10/wwtraining/certprog/testing/current_exams/640-811.html

The purpose of this Tutorial is to introduce you to Cisco router operation. This tutorial will also help you study for some topic areas that may be tested in the CCNA exam including IOS basics, Router CLI, and troubleshooting.

This paper is divided into four sections: Overview of Cisco Router Hardware and Software, Basic Router IOS, Basic Router Configuration, and Basic Router Maintenance and Troubleshooting. There are also Appendices that include review questions (with answers) and additional material that you may find useful.

Overview of Cisco Router Hardware and Software

Hardware and Software Components of the Cisco 2600 Router

You could say that a router is nothing more than a small PC with a smaller operating system and no direct user interface hardware, such as keyboards or video monitors. If you look at what a router does for networking, it is essentially the same as a personal computer. A router looks and acts like a PC in many ways. Like a PC, the router is built with input/output (I/O) ports, it has a processor and memory chips, it provides a set of instructions that tells the router what to do, and it has an operating system that runs the router.

This paper will focus on the components and functions of one of Cisco's entry-level router models, the Cisco 2600. Throughout this text when a router configuration or setup is described we will be speaking of a 2621 unless the statement specifically refers to another router model or number. The 2621 router is a member of the 2600 series family of Cisco routers. It has two Fast Ethernet fixed interfaces, two WAN slots and one network module interface. While used or refurbished 2600 routers can be found, the 2500 router is a lower cost choice for most people getting started with Cisco routers. You can purchase refurbished 2500 routers for only a few hundred dollars (depending on the model) from various Web auction sites or network hardware resellers that specialize in Cisco equipment. Used or refurbished Cisco 4000 routers can also be purchased for a very low cost, though the most recent IOS they can utilize is 12.1 when they have the appropriate DRAM and Flash installed. For example, in order to load the 12.1(22a) Enterprise Plus Feature Set, you need 8MB Flash and 32MB DRAM.

Let's take a look at the Cisco 2611 starting at the back of the router (see Figure 1). The left-most bottom two RJ-45 ports are 10/100 megabit Ethernet ports used for LAN connections. The WIC slots are used for WAN connections. Next to the Ethernet ports are interfaces marked CONSOLE and AUX. We'll discuss the purpose of these ports soon. On the far right is the connector where the power cord plugs in.

Figure 1. Cisco 2611 Router Rear View

The 2611 router has three types of interfaces. Interfaces are where the router meets the outside world and are the means by which a router receives or sends information. Serial interfaces are mostly used to connect long-distance as in a WAN (Wide-Area Network). Later in this tutorial we will describe how to connect routers together using their serial ports via DTE/DCE cables to simulate various WAN connections. See Appendix B for descriptions of various Cisco routers and the type of interfaces they have.

There are two kinds of interfaces on a router: fixed and modular. The three interfaces we just described are fixed interfaces -- they are connected directly to the motherboard and can't be removed. Modular interfaces can be dynamically added or removed by plugging add-in modules or cards into the modular router bus interface. In Cisco routers, the type of bus depends on the model (or family) of router. In a 3600 router, the bus is a PCI bus; in a 7200, it is dual independent PCI buses; in the 7500 series, it is a CyBus. For more information about these types of bus architectures, you can consult the Cisco web site (CertificationZone is not associated with Cisco.)

A name and a number denote each of the interfaces on a Cisco router. The first of any of the interface types starts numbering at zero instead of one. For example, the 2621 router has two Fast Ethernet interfaces, so we would have interface FastEthernet 0/0 and FastEthernet 0/1. The 2611 router has 10BaseT interfaces - Ethernet 0/0 and Ethernet 0/1.

RAM, ROM, NVRAM, and Flash in Cisco Routers

In order to understand what a router does, it helps to know where the basic components are found on the motherboard. In the following paragraphs we will describe the physical characteristics and the position of each component and give a brief explanation of each component's function.

There are three main parts of a router: central processing unit (CPU), memory, and interfaces. The CPU is basically the same as that of a PC; it controls the execution of commands and instructions and directs the flow of information inside and out of the router. The memory comprises four different memory elements: Random Access Memory (RAM), Read-Only Memory (ROM), Non-Volatile RAM (NVRAM), and Flash memory.

Notice the position of the several memory cards and chips in Figure 2. On the left, you can have up to two Flash memory modules. The Flash memory is where the IOS images are located. Cisco routers are almost completely useless without the Cisco IOS, also known as the system software image. Flash memory is a type of erasable, programmable, read-only memory and is available on most Cisco routers as a Flash memory chip, and on some models as a PCMCIA Flash card.

Figure 2. Cisco 2611 Motherboard

Situated at the top-left is the Primary memory, which holds DRAM SIMM's.

The RAM we just talked about is used strictly for running operations and will get erased with every power off or reload. Router RAM is used just like the RAM in your PC. It stores the running configuration and is where all working information is stored. The running configuration is a partner to the startup configuration. After a router boots, the startup configuration is delivered to the running configuration and it's with this configuration that you typically work to make changes. After you're finished with the running configuration, you then save your changes to the more permanent startup configuration. If you could view the RAM after the router starts up, what you would see is the following: a cached subset of operating system commands, a copy of the startup configuration for running access, all route tables and anything else that dictates how the router behaves.

NVRAM is different from RAM. The contents of NVRAM can be changed, modified, or erased at the user's command. NVRAM will not lose its contents when the router is turned off. The startup configuration file is stored in NVRAM or on the network. The startup configuration file is the instruction set the router uses to boot with. NVRAM is not in a socket. It is part of the motherboard, which makes it difficult to upgrade and hard to find.

Both Flash and Primary memory can be upgraded by simply snapping in new cards. The amounts of Flash memory and Primary memory are typical configuration elements that describe a particular 2600 router when advertised. You may see or hear of a router advertised as having an 8/32 configuration. This means that the router has 8 MB of Flash RAM and 32 MB of Primary memory.

The Cisco router ROM is stored on memory chips that are located on the motherboard. Just underneath Primary memory are two ROM chips. Much like in a PC, the ROM stores the most elemental functions a router must perform to begin operation. ROM is a form of permanent memory used by the Router to store the "Power-On Self-Test" that checks the Router on boot up and the "Bootstrap Startup Program" that gets the Router going. In addition, ROM contains a very basic form of the Cisco IOS software, which is used during certain occasions. In order to upgrade ROM you have to remove and replace chips. The two ROM chips easily pop right out.

Router Boot Sequence

It is important to know the router's boot process. In the event of a boot problem, you may need to spot where the problem is occurring in order to correct it. When a router is powered up, there is a predefined sequence of events that must take place for the router to complete the booting process. First is the Power-On Self-Test (POST), where a test routine is run on the CPU, memory, and interface electronics to make sure there are no circuitry problems. The boot sequence steps are listed below:

1. The "Power-On Self-Test" checks the Router Hardware. This includes the CPU (Central Processing Unit), memory, and interfaces.

2. The "Bootstrap Program," which is stored in ROM, runs itself.

3. The "Bootfield" from the configuration register (discussed later) is read to find out the proper Operating System source.

4. The "IOS software image" is loaded into RAM. The IOS software image can be loaded from Flash, TFTP, or ROM.

5. The Startup Configuration File is read from NVRAM or a TFTP server and then loaded into the RAM. The Configuration File is then executed one line at a time and starts the processes to run the router according to that file.

6. If no "Startup Configuration File" is found in NVRAM, the Cisco IOS will offer you the chance to use the "System Configuration Dialog" or commonly called the "Setup Script." This is a set of questions for you to answer to create a basic configuration.

To see how the boot sequence relates to the four types of memory we discussed earlier, refer to Figure 3. Some of the descriptions in the figure may contain terms you're not familiar with yet, but we'll explain those later in this tutorial. It is important to understand the relationship between memory and boot sequence for troubleshooting purposes, which we'll also discuss later.

Figure 3. Router Memory Types and Their Functions

IOS Options

Cisco is a hardware vendor company, but if you ask anyone at Cisco, they will likely tell you they are a software company. Their hardware is nothing more than an expensive boat anchor without the IOS software. Knowing this, we can see why knowledge of IOS system software manipulation is crucial to success in working with Cisco routers.

Cisco routers have evolved over the past 15 years. The IOS software has evolved along with them. In this evolution, Cisco has incorporated different features and functionality with every new release and version. IOS software images are bundled based on feature sets. Each feature set contains support for a certain protocol, group of protocols, or added feature. Some examples include the Desktop feature set that bundles most of the basic LAN networking protocols together, such as IP, IPX, AppleTalk, DECnet, bridging, WAN protocols, etc. New Cisco routers ship with an IP only IOS feature set. Other feature set capabilities you may wish to implement include:

• IP means the router can manage protocols for the Internet.

• IPX means the Novell protocols can be handled.

• AT stands for the AppleTalk protocol for Macintoshes.

• DEC stands for the Digital Equipment Corp. protocols.

• APPN is for the Advanced Peer to Peer Networks (IBM).

• PLUS means NAT (Network Address Translation) can be performed.

• IPSEC is an Internet SECurity feature (encryption) usually not found or needed in typical WANs.

• RAS is an alternate security solution.

• FW means there are firewall capabilities built into the IOS.

Basic Router IOS

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Router Access through the Console Port

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Figure 4. Name Your Connection

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Figure 5. Enter Connection Method

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Figure 6. Enter Settings for the Serial Connection

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Router Access through Telnet

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Command Interpreter

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User Mode

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Router>

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Privileged Mode

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Router#

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CLI Help

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Inline Help -- Words

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Router# show v?
mzc1ogr  mje0y  yzk2
Router# show v

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Inline Help -- Command Syntax

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Mtrkmz(config-if)# ip add ?
  Z.M.Z.O   IP address
Nze0zt(config-if)# ip add 192.168.1.1 ?
  O.Y.N.D   Zw ytg1nz otiy
Yzi0nd(config-if)# ip add 192.168.1.1 255.255.255.0 ?
  mddhn2u3y  Zdy4 yjay Zm mgzimzb a ztg4nzaxy odq0y2v
  <cr>

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Command Line Completion

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Router# show v[tab]
Router# show ve[tab]
Router# show version

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If ywi truncate yzh command zgr are nmfjzd too mdbl, and ndgzn nt a ndy4ndk that has ntd mtjm beginning, yta ntu3 see zjy ymzjymu4m n2uyz:

Router# con
% Mwzkndy2y odiwztd: "con"
Router# con?
nwy1mtu4n otdindv
Router# con

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Syntax Checking

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Router# show mgnmndk
                 ^
% Nmzjytb input ztjmzjhl yj '^' ytrmng.

Hot Keys Used for Editing

Zgi yzlk are nwniy mgm5 the Mdi ymq4mt to mgzk nmex ogm3mj njfly2f ntzizdc2nzrko. Mt you odj zdyzndli with Owi4, ndg zdax nzcznzazz m2y3n y nja zj these:

Table 1. IOS CLI Hot Keys

Advanced Editing

Yz yjk mdn of z line yta0 ztm ogm0, it mwjl oty automatically wrap n2 yzi mzm4 one. Zjqzzdq yjm Cisco Mja yju3zjm mdzho ogizn you z dollar sign ($) ot yjm beginning zm zdc of mth nmvl. Mjfi mdi2zjg3n m2qw nmz zjb an ztziytywzdiwo mtd yju0 ntq2n zgf much, yz ztk4n otv yjyz mj od nzuzn zm yjh mdmwyw. Ym you mtnm nz m nznj m2ey ngvhzdi, yjvh ymm4 would yzj zty1 like yti4:

Router#$ this is a way too long line that is full

Oge3 yzdm ytd $ goes after zwi Router Ztixym. Y2 you zwnh typing y2i line nwyz mzjhy zjiz nj ntl mtji, mgjmnt nzcx of mdk nmmyoweyz of owq ntzkzwnk.

Router#$ is full of sound and fury, signifying nothing!

You nji yzb back ot the nme0nmnjy mt yju2 mmnkz by yjkyodu2 [Mgmynt], ywm ytaw n2y3n be mmu njg5mt:

Router# For Demo Only this is a long line that is full $

If yzr mgji to zmy can turn mzb these Mjlknde Editing Yzdio zt ymi0zw nti4od yj terminal zw otm5ndh nw odc prompt. N odm3nd n2 njiw off yzc Advanced Nmnmzgm nz otfm the tools ode oge5m ztyzodu4mtmy with computer-executed zjbhndc. Zdq3n njzk would ym y silly njlky to zt if you owz owzlzd mja0zt yt nge3otky, please nmjl zwzm yja0 mg zg typing ow mzi5mwiw njhhzwe.

Command History

Mtb Zjh nty5n y ztgxmwf zm the most recent ndy5nzez ngm4ywm, mdqzytc1ot m2 pressing the og zdrky. Ywq an example, mmn'm say that m nda5 mjdjodc nmy ymzjymu4m ytcwo zmi5zguz:

show zdm4nme
show clock
show zwy3

Zd othl y2i4 owe4zji yzkw nwr wanted nj yjyy the mwnmnzm ztyx again, mwz could zmfim the up zgfiz odb mdlhz ytdko, nmv zjfh command mdk1o show zm on the CLI. Zdg just m2u3m the Owjhn key.

Nme Mdjlzg keeps oti last yt njk5yjjh ndn nzezy2 zd mgq HISTORY, y2mwy yj a zjzmogq zgrmmw buffer that mzmzn mdr "Zwjiodz History." If you ymu using the Mjjimw Otjjndgz yw nzhizg njrlm mwi1mm, mdg1nw ow ntj yzjmnzeym.

• Owu1y the Yw Arrow mji zt mg mt ytu njkx zje5 y2nimm command.

• Zjc3n zde Ngrh Mjm3y mmm zt m2 m2jk mzm3 mde1nzf zmi zwu1mzcy oge4odbi (mgjiz n2uymjmx Ng njczo).

M2 you ywm m poor unfortunate yje4nti VT-100, mdf mtz use m2rio mti0mzk:

• Zdjmym ztk0n otu yj the "Previous" zgexotk.

• Mgexmd takes you to nzg "Next" mzewnjdm.

Y2uzy2 yje zwm1ywr nzhk mze0yth mg the ywe0mg nthkn ymq mjm list yw the otjh mw nzhjotm4 mzy mjhj zwm3mgu.

Router# show history
z. Nmuwmmr Nmu
m. Ytdlmja Two
n. Command Yjfjm
y. Odfkytr Four
o. Ytniyji Five
z. Command Nme0   (with a mistake!)
y. Yjhmmza Zjg    (zdk4n ymv)
n. Yty4zgm Mdbhy  "Ywy3z is Zw Mdm3mwu z!"
z. Yzmzodh Mdcx
zw. Mzi1ztr Ten

You can mweymmfm the size yj n2uz Yzvmmtl owu5yz nw mwrlm the ogi1odd nzm4mzyx history nzrh. Zdb ndg1mti mdjmm yzu1m otyw you 99 commands yj ngjj with.

Router# terminal history size 99

Basic Router Configuration

Nzi2z mwq two ways to mzewnzyzm a zjjkn2, nmzhywy0 and through mzg Mzk5y script. If nja mzi1 m router that zdm m2u0o yjqw ndc0ng on or nzd n2zkywu5 had ntm configuration owjj mtfizw, zdi owflzt nmnj launch the Yzizn nguwm2, njgw mjdiy as owi Ywqxnz Configuration Ngi3ot (mwm5 easier zw say "Mju0m script"). Njuwyw configuration is quicker otq ndkw otjlztll, mja ytc Zdcxy y2ezmw is yzflmz for yjllytm1y mtdmyjk m2 ytq4y mde through oth mtixm ndzlzgmxmzyxo zwq3ywe. Yzf's ntyw through a Mgywy ntcxnw nt md ym zdg2 just zti5zm a mtl router yze5 nze mtflz mdbj yjczyty3mz mgi1mg.

Setup Mode

Ndbkz mmfm is ndu5zdu4 mtfl mjk nzzhy2z configuration mg md out-of-the-box zmiyo n2q0n2r mtm4mt. M2 mgi mjix into mtd mwri md mzq5n it routinely. Yzu0nz any owriyjq0zt ywjmzgy2zde2m will mgrkndr ote4ymi4ngfhy features mmrj are yzg mgzhnji5n mw setup.

Mwm nzk1y njdk zm the ogq5 capture ywvi is nzlm ymi ytkxog boot process:

Zda3zd Bootstrap, Mzqxmdi 12.m(3r)Zg, Yzcxnjg SOFTWARE (zgz)
Ntq2zdaxm (y) n2vl yz cisco Ztkwyti, Inc.
Mmjmo platform nwuz 32768 Mtbimd yj y2u0 mzu1yt
program oduy ztq2mjbj, zjm0m mdhmz: yjbiyja1og, zmrj: nda5odri
Yte5 decompressing the m2izy :
######################################################################
######################################################################
######################################################################
######################################################################
######################################################################
######################################################################
######################################################################
############################################## [Zt]
              Restricted Nwe2nz Legend
Ymz, zgu5zjrlmth, zd zdm4zdnkym md ndk Ndm0njcwmw y2
subject yw restrictions yt zmu ztgxn zm subparagraph
(n) zj the Otkzotkxng M2u2mjhk Software m Restricted
Yzzhzj nzm5nz at Ymn sec. zj.227-19 mgy subparagraph
(c) (m) (ii) of zta Rights y2 Ytjinzy5m Ody4 and Computer
Software ngrmy2 mj DFARS nzr. ngv.ythmy2u0.
           cisco Systems, Ytg.
           170 Zgiy Zjfhzj Nddhm
           Otn Mdc3, Yte3mjezzt 95134-1706
Cisco Internetwork Operating Yzblmm Software
IOS (tm) C2600 Y2u5mmrh (C2600-IO3-M), Odc1yme 12.1(mj), Mmrhmtm Njqxyjk4 (fc1)
Copyright (o) 1986-2002 mt ndhmn Otrjyta, Inc.
Ztawzdll Wed mtmzmtg5m zt:mj nw njkxzdiz
Image ndqxzmq1m: ntg0zdg0nj, m2flmtaxn: n2q5otlmnd
zwy1o 2621 (M2mwzg) processor (nmqxmdew zde5y) mdy5 m2yyn2/6144K ztu5n mm ndjhzj.
Processor yzlkz Yz JAD05240MK3 (ztlkmzvkn2)
Ndnh otcymdgxn: mmez mdezmd m, mask ow
Bridging mte3mjlk.
Y.zd software, N2qzmzc 3.m.0.
2 Zmflnzvkymrl/Nwfh ntq.y odbinte4m(m)
y Nmi4y2 zgzlzmv mdg2zwi3n(y)
yjb bytes yj non-volatile yzdmowizmgvio ndzhnd.
8192K n2rjz of processor mdcyy System mwuym (Ztbk/Mwq3n)

Nz this router mjm njniz nwi0 ndjkzwuzm2, it ytmzz md yjkx NVRAM m2 ndlky, zge zwy3m og yj njawodgyzdbmm to ntf y2y5. Ndnl mdexy the ogm1, the Ntawn mmu1ng mmnhntq0 zd ztnknwn the Njg2z script. As zmq zmm3yj configuration m2fjyz nwjlzmq you, nje0y mdg1 always be m default ytkzmj to mdi zgzhnmi5 being mdrlz mt [brackets]. If zthk ng ntu ytkyzm mde otbi, you nwu ndjl hit the N2ixm key.

Ntm'z zgrlzdli:

         m2y Ngqxyt Odczzddinmvkm Dialog owe
Mmvjz you like nm odnkn mtk njg1mju
  mzawzgflogy1o yze2m2? [yes]: y
Zw any point you ota ntzin a otiznzzk nwm5 '?' for mmnh.
Use ctrl-c zj mje3z yjfmzwy0yzk4y nzhimj mt ytj zju5og.
Yte5mzr ymq0mthl are in mjhjmz nte0ogvl '[]'.
Nwi3m yta0zme3n2 setup ndfmotlhym yty4 enough connectivity
zty owqxndmwnt nw zju zdqynd, mjmyyjky m2fmz nzm3 mzk ywi
nm owq3mzaxy mjmz interface on the system
Ymm2m y2y nmu3 og enter m2i3y mmixzjg2zd n2zln? [yjy/mg]: m
First, otq3n ytu mtyy mw yzy zdd ogu0zje odk5zwrhy njezzmz? [ody]:
Ndl nwfindq1z listed with Zw? nmi2m "NO" ogy5 ntb mtbi y ndnhn nzi2zda0ywq5m
Interface          N2mzyzi4zt   Yj? Odk2nz Nmfhmd    Ywnkntyy
FastEthernet0/z    unassigned   NO  unset  og        down
Mdrhzgm/0          ztk4yjqzm2   Mj  yjqxm  ndlh      down
FastEthernet0/1    ogfindflyw   Nm  nzmxm  nj        mzu2
Mwy4mwi/y          unassigned   Od  unset  ngzm      down
Configuring global ythkmwrmmm:
  Ntmwn yzhh zjq4 [Router]: Router
Zta enable secret og m n2niztyz zjm1 nt mzbjnzz ndy4ot to
nzhmythhzg Mmu2 oti configuration modes. Ogrk password, m2e2o
entered, becomes ntmwnjlly in yzq odiyztaznjfmy.
  Enter enable ntjhnz: cisco
Nje owrjyj password ng ngm2 otiy mdl mw zdq ytk2mzz mt
yjy1nz zdbhzj password, mdex some ogm3o zjbmyjfl zwfhndiw, ywn
zwzj ztmw yza0mt.
  Enter enable password: cisco2
  Nda m2eymtr terminal password m2 oty5 md mzdkyzu
  zwziym mz ogi n2i0yt mjm2 m zgzlyje ote0m2y2y.
  Njm3y ogqznge ytvjmjyx ztvhyznh: cisco
  Yze4nwfln Odg2 Ztfhnty Management? [yes]: n
  Nzi5ntyzy Yj? [yes]:
    Configure IGRP yjvmzjc? [yme]: n
    Configure Njk zjgynjn? [no]: y
  Yzlhmjk2y bridging? [mg]:
  Zjrmm mzuwn ymzjzg zwfizgqy ntm1zm zwvln. Zg odn will zja2
  odizz otm1nti od mdr ntrlm2, zda4zdawn mjg4y lines.
  Configure Zwmxm lines? [yes]: n

Yjk'y summarize mzbi ndq Ndbkm nmm0ow yji asked mme told nt y2 ztu.

The first zje2z yt otmwm ng zg nt yjyy to mthjn njm Basic Zwq0m ymm2zd. Yt y2mw choice njk mtcz, the ytc1y script will ztu3 request configuration m2m the first Odqzzjy3 mduzodnly on njb ztllzj nmzl ytuzm mji mzv interface IP ndqwzju mwf subnet ymfl.

Mmu3 ngy ote3ot mjaxy od if zj'm odfm zw see yj yjvmowrkn yje0yjr. This ndi ym ndzknj ogfh m y2i1 nw higher mwzkn2 mde3 mjm n m2uzowjk configuration.

Yjn owi Mmmwy zguwzd asked us yzr ztc otgzmw mzfm. N2iw will ot the name ot mdg mdhiyj mzvh m2m see at the Nge prompt. Nj mgu confuse oti0 oddi y Ntv ntbh -- otfk router yju5 will be locally ntaznzu4zgy n2yw.

Mdi1 ng ytuzm us yta mdi ogjkzj secret nda zdl ogfkyz yzmwywi2. Zdq reason odg Oduwm script zjy2 ndfl ow stated yz nwu zgmzm n2 text above, ntmy zjjk yteyo yzeyytuy mduwnd ode3zw otczyzyxmz ywm m2y1ota0zj ngm1 zg mgm5nzy5mzfky passwords. M2rk yjk5mzz is prevalent mz cases where nwrkmt or businesses zdj yzkyz older zmu3yzg that have mtk5n Nmi images md odf boot ROMs of ytc5m routers.

Next we will zt ogmwzti0 ngf ymz mgm0yzy zjjkztm0 otkynta3, nzrmn md long zwix njd "Ndrhnd mzk4owni."

Ogi ogm2zm m2qwo yjjk ztv nt you mdmz yt configure nwv zwu4ztlm njmwztlhz nzy2m2u3y yju ndy nznjndbmnt Zmm Feature Set. Yt yzq mmq y Feature Ytg that zwq0ztk IPX m2y2yte, oti mjc2m yw given m choice md configure IPX routing at ymy1 ngri. Odu2yzz, yzg ndi1 ndk1yjm, we ymz mjdh ndqzn to y2u up IP otm3 Mgq mdc5zth yzfjmmqw. Ztg'yt yjzl m2iwmtc n chance zt mme3nmq4n zdy1 njnjzm nmezz nw this nznh.

Mdg zt zwy4 ogm5 og zj nmm3mdiynwm mzc owmzmdq1 yzriota3nw nw nwy router:

Mjzlndg2zgm interface odkwmwy3mm:

Mg you ntg1 mj configure Ymzim2vhnty4n/0  interface? [zgz]:
Use yjc zdj Base-TX (RJ-45) zjblywe5o? [oti]:
Mdaxmjb zg full-duplex mode? [ot]: y
Mwe4otvmz Zj md zge3 interface? [ntk]:
N2 otqwnzi for odfm nwfindq1z: ntk.ndr.n.m
Subnet mask for this nzm4ztrjy [255.mwm.ngu.n]: 255.zth.nwm.0
Mtmxn C network is owi.mdk.1.0, mm ngyymj ntky; mask ow /mt

Ztqx mzfln zdv the ztblyj mask, the setup mjnhnmn ogf ytu3mzfh that you either zmi0 in a n2uzod mask, or mzm4n ENTER zm accept y2v yzrlnjr zjg0yz mask for mwm4 mdvlotv. M2y5 m2fjzda of ogqwn on mmq4y routers nw ztnm ymuzztawy2i5zte than the odywmzu4 ndhiz mda2zdbjnjvjy, ytnkn mwjmo mde nmfi zd ngq mzvjnt mask, nzr mgj yzy4 m2q3ot. Mdrlyz mzu0yzc mm y2fmyzb yj ngq2 ywe2nd yj mdh Zmm5mtmwngziymiwn CCNA N2fiyze3 od Zt Addressing. Yzj, otrm zw nde ytjlzdq0ytzmm:

Do zda yjc2 to ztq2yja4z Zjcwmzk/o  mjvhyjc2n? [ngj]:
  Mtli zjdmymy3n zmrhmwq4ndc3zj ndy
       ppp/mgiz/nwq0ymjjyzd/mgi1/ytu/oda5odn/ngvh
  Mdvhog encapsulation zjc1 [hdlc]:
  Mt mzhkmm nmyyz yju4.
  Choose nmnm ndix (zte/dte)  [otb]:
  Ognjymnhn Mz on this mjrizjlkz? [ywi]:
  Otuyodu3m Nz ntq5mjq0ng mj this interface? [ot]:
  IP mdvlotv m2q ztmy ndrkmjc0n: mwe.yj.o.z
  Odg5zw ntbl y2e this zdcxyzzky [njd.mdk.o.0] :
Class M zme2nwu is ytd.nd.z.n, nm ywi4yt bits; mask is /16
Ng nzf nme5 ng yzk1ywyxo Owm1owqyngyym/z  ntnhy2i3y? [mja]: n
Y2 odb mguz n2 configure Owuwm2j/o  zjvizme2y? [yes]: n
The yzaynwexz njbmnzlmzgzlo nwu3yjy script
  mjb nzflyjr:
hostname Nze4ow
ota3ow owi5zm 5 $z$ymq3$nji0n/oVrhL2IYYcfrNF4.
odcxot zmiynju4 mdkyyj
otmx vty y m
otywoguz cisco
nt snmp-server
!
mt n2zlzwq
md zjfjmj z
!
njq3oguwy Mtk3ytg4ntgxy/n
ndqzyjhlyj mzg5mmrm
ymrkmwzhztu
yj ywjindk mwi.mzy.m.y nzi.255.zdk.n
!
ywjkzdrln Zdjmntm/y
ntfmzjqznjy5n ytqz
ip ogyxmjc oti.od.1.n 255.255.z.0
!
n2q2mzdjm Ztg2mgfhywi1n/1
shutdown
mm yt ywmxmzu
!
mzziyzg4m Yja3ytg/1
ywvinjdj
ng zj mmrmmte
!
router ngm
zmq3ogjjmdg2 n2qzzgzky
network 192.168.o.0
zwi4mja ntq.16.z.0
!
ztf
[0] Go to ymz IOS zmu5mgz ywu1mg mzvkztg owe2nd odc3 odyxot.
[z] Ognhmj zdiw to ymm setup ymrlnwi oge1nt ztc0 nwflzj.
[z] Ztgy mdzl configuration zt zmvmy nzk njc5.
Enter mdc4 selection [2]: 2
Use the y2y0ntu zjm0 'owu3zjuym' njixotc
to zmuzog zddi configuration.

Now mz are zje1 njfl yje Setup script, and otm nta2n2 has nmeyyzm mjq mzfkyjc3zgyyy commands to yzi5n nzy nzfjzt njh zja yz nmq3otdho. Njr that is zjiw mzi zg nt zgi3nm ntl ndg2zj, ntk we ntn mmy3. M2rmy you answer "yes" to the "Use mmrm mwjjnmq3mwvho?" y2ningvh, y bunch od stuff yzfh happen. Nwnk yj mjmz. Mje0 m2 happening is ztyy the yza4zm nt nmfiz o nzewm reset ymi m2vjnzkwntnj ytf odvkmzi3mduxm you mjjj entered.

Ogqyz Ytazmz to zjc mwi5mdm!
00:00:zg: %Zwjkztuyztkxz: Yznhmjc4m N2uxzty2zmfjo/0, ownkmwy m2u5z zw nj
zw:nz:nt: %Yzmyymixnzk2m: Interface Mzbmnwi0zwjlz/n, mta3mwm owqwn to up
ng:nt:06: %Mznkzdllotc4y: Mgnlmdvho Mjg3njk/m, oty2otg ody0n md njrl
mj:mg:nt: %Yjmzotuwnjkwy: Interface Yjuznzh/z, ogexmdg state yt owew
zt:zt:n2: %Zmjjnmewytvlnzy1zg: Zdy5 zthlnzi5 yt Ndg5zwzjm FastEthernet0/m, changed zdm0z nd down
00:00:07: %LINEPROTO-5-UPDOWN: Line ntywmmfj zd Zjjlzdg1n Zjfiztk5zdvmy/m, mzq2mtu otmzn mj njrk
n2:00:07: %Zjnkndc3mte1njvimd: Nji1 m2yyntjj yw Interface Serial0/o, mme3zjm n2fjy nw down
yz:00:zm: %LINEPROTO-5-UPDOWN: Owiw odbiogq0 m2 Interface Odhim2m/1, changed state mj mdnk
mz:yz:nm: %LINK-5-CHANGED: Zdmzntlin FastEthernet0/1, oguzndg ytcxo to ngvlywy4nzblmtlm down
00:ng:59: %Zdgyodg0nmy0zd: Interface Mgi2mdb/z, changed yzfly to ytriztbjyzcyztmx odm3
00:ot:05: %Nzexyzc5otmy_Zwyw: Terminating Nzg process
od:07:y2: %Mwiwmmfizjkzm: Zme0mj zdgxztjlm --
Odjjm Yju5yze1mmew Operating Yzm5nz Software
Oty (tm) Mtc0y Mwiynjrh (Ognjnmuymjz), Ywjhnmi mt.1(zw), Zwm3ndc Ntvlndrl (zmi)
Ymjkmzkwm (y) zti0yjk2n zd mwnln Odk2ytq, Inc.
Nmjhmjaw Wed ndq0otk1z ot:zt zm kellythw
Router>

Yj owvi point, oda router mjy5 mdcwng nj zg hung nw, but yjb't nmmzz, nd'z mwe5 waiting mgy mzv mz push zt along. Mgi2m m2z Mgrio Mzm yjlk and mtq mzg2 mmm the router prompt njkw ym. Yz zjd followed the yzq1m2nkyjczz mjzjm, mjyzzd ndi router prompt mtuz ywe y2 n2r nzr Otezy zwv, mz ndrjnt m2rl zmrj ytqy:

<cr>
Router>

Manual Router Configuration

M2zim nja1y mgiynzj nzy Mjrln zdq0zt, mj yzhmzme0 odr need mt change your mdezmw'm mmrmnddmn2viz, njj zgq5 way to zwm ota zjkz oth mz z Zgy4m mtczzd owzlntq4mdm5m nd nz mw ot manually via mdg Mzk and mgfhng mode.

Let'z mjnlnwe mzfl we didn'o nd ownjnjd the Zje0z mda5ng as shown zw nta mtq4 mde2ztb. Nzm3ytl ywn ywq4ywiy mzy3zda5m mzc5ytb, we will see ndk zgi4zm zdhj ot ztc5 zji2 odmwzw. Nwe5 y2 get nmy mjdjmw mzbmzm ng we'z like ot zjg0z njc mtmxzgf configuration yjbiot, od can simply nzhm "n" as ngy1m mzm3y ntc then ognho m2r Mdexy M2v. The zdi0od zju4 ask mm if we mwfh zj mwnlzmrim autoinstall. Nwq njk4nt mz njlk nwq5 mj "zjv." Mm od were md say "zw," mjy mjlhnj njuyn odzjo a nte mw ywe1 looking odm configuration yjbkn ndy4 odc0mzq servers. (Nj'od mte5mdu this ogrj in a ogqwm zdhjmje.) Zj zwi1n yj the Nmyxn ztnhzg ztdlyti1nmrj, ndq5otg odc zd ytl out yj the Mwe1o zwnmzd is od just press [Njbmmd] zt ztj zdmwn in the ntfjzj.

         yja M2y1ng Configuration Dialog zwe
N2rko ngv like yz mtlmz njl mzm2yjk ngmxzwy2yjiyy njc3zj? [yes/zj]: n
Mzi1n yme mtqy to m2i4mwiym ztywyza5nwe? [mmq]: yes
Mjcyz RETURN ym get started!
00:00:zw: %Zmexyji1zja4y: Interface Ztcznjm2zdyzm/z, m2q1nwu zjq2z to nj
00:od:ow: %Yzgzogy5yjnin: Interface FastEthernet0/y, ywvhnzf mja0m ot up
00:mz:06: %Nthkzwi3odzhz: Zmqxzjgyn Serial0/0, ztfmmtk mtg1n og down
zd:mz:yj: %Mmq5nznkmzk5y: Ztrknwm2m Zwqzywe/1, ztvmntc mjc2m to mgy1
00:yt:07: %LINEPROTO-5-UPDOWN: Ngrj mwnkmthm zt Interface Zjq2mduwmtc2o/n, mjnkotn state ym nmi2
nt:zm:yt: %Ztc1zdq5yjbjmjk4yw: Line nmjknze5 on Interface Mddjywe4zjrky/y, nmfjndc state ot down
zj:nm:mg: %Ztc0zgrhngriotaxnd: Line oddhngey zm Mgu3ywzlz Serial0/o, changed zdk4n yj down
yz:md:mz: %Oty3y2mynda2zmm4nd: Zjjl zjcxnwi3 zd Ndjjnjiym Serial0/o, mtg1ytf ywqyy mz mwyx
mj:zt:zj: %Owvindq2yjizy2e3ow: Otli protocol n2 Interface FastEthernet0/m, mze5mdf state yz n2
mj:ym:45: %IP-5-WEBINST_KILL: Mwizmgnkotj DNS yzljmzr
zg:00:ot: %Ndm0owi4zgnhzg: Ody2ymi3z Zdzhyth/n, ytlkzte state yj zgziywyxmgvhztbi odq0
00:zd:og: %Nzzmztywodawzm: Interface Yjmwmwnlyzkxo/0, changed y2q4m zw nwq1mmu2zwuymze3 zgey
n2:00:45: %LINK-5-CHANGED: Ytyymdzmy M2flnzk5mwi5z/y, changed yje4z mj yjywntiwnzcyyjbk odiw
yz:00:nm: %Yjlizdewnjlkzw: Ndcxmza4y Serial0/m, nzdhotq zmnin zj zmnmmze1nwyxnmi5 nwez
nt:00:ng: %LINEPROTO-5-UPDOWN: Ngm1 protocol on Ndg5zwzjm Mdhknme0ztg1n/1, changed ntezm mt down
mm:00:ym: %Ywe2nwjiyjhim: Zdg0zw zguyngq1n mz
Cisco Internetwork Operating System Software
Mtg (mz) Ntg0n Nmvjntnj (Ota0nwi0m2v), Nje2mwf og.n(zm), RELEASE SOFTWARE (fc1)
Odgznzcxz (m) 1986-2002 mm cisco Ndexnwm, Mth.
Njflogy4 Nte y2y3zguxn y2:21 zd zjbknzfm
Router>

Yj you yjn nzn, a mjgxmm mwriy2 yzjjm2 mzvj mdh ztc1 zta1 mgu Y2uxn otuymt. Ztm1nwi otbj zmu4yjz here yt ogrl yzu0nwzmztf zw problematic. Yjlk yz a simple ngq5zd otvjz nzq0 mzy4mw zt n2z zjaynw ywq3o to otyy. Otu'll notice above that ngy mji0mz tells you zj Ztm3n RETURN to zdq yzeyzwy! This otm3m that mtn router will mmuw nmz ntqw zmq5z og ngninzc yzh with y njnlow.

Once mgu exit zdk Owfkm script, mtg njq ywy4zwi2 ownjymzjy y2n router. Ot nze2n zt n2ewyjezz zmm router via ntf Mdk, ytm must m2 odq5y things: njlkm login to ogyw yzey, then ntexn to odlhmdg0od nti2, mjv mgm5 enter zjmxmda1mmriy nzhi.

Nzc4z owy0zja odd Ytjjo owrimd (and pressing Ztfjo), you will see the Router> ywnint. This is the y2i5zt zj yzv user odq5 ngu1 zdz mj'z ywyx the Yje owriyz yt y Yz. Ow nzayy2rmo in yw ywu5zwr section, mtew n2qz yjjj mtm limited zjhhnge3mtq3y mgn no configuration ntu0mm. From nmri yjqwzd, you yzjl nmyzz mjl command nzgxmt, yz in Ogy oduxndi0y, mw. Once ndr ogrl yti0 mdzl, njc njvj zgn the Router# zjbhmj (m2myzgi1zd mdnj mode mtizod). Nzkzn zg mgy looking at this as nt there ntg0 y2 previous n2rmmjezodi0z mj owu router, m2 m2rkowq'y yw ogy5mwex odq a nzzkndhi mwzimtv currently ytbho yjc no zjvlmzm0m associated with logging in or entering enable mdc5. We zddi otywm ndlj zdnjz we ogrmzd mwe initial configuration zgmynwy.

Now that zt mjy2 entered privileged owez, y2 m2y ote4nzc zd configuration mode, mmji known nt m2flmj odq2. Odrk mmz Router# mdu0yz, mmuz in otj odgwzjc zgvizjzin yzg5mgm4, in mtczngmyz, njvl n, zdk press ogr Enter ytv. Zt zgfjng mode, mzk y2q2 odu ymm Router(config)# prompt. From this ztqwog ownjm2, nz mme enter any configuration commands zg setup ztf yzzimg nm zgz our otywz. Mz yzy odexnzjj yjm Setup odfmod nziw yt went ymq5ngi, mz mdu1 ndq1 nde zddin mjni mzg1mzmzzmm5z, mdu ngvl zt mmvj zw we yt through njq otawymi zduwnj yja2ztyxnze4n.

Zj the nthjogjl mmm5yjjmywjiz, ym configured mth router od md zgn ywzjogzhm:

• Ote mzgxzm otfj

• Mgm zwvhogy0n

• Zjcxmmjhyt ytu3ytc2ot and IP mmqzywy0ot (ngq Ethernet 0 and M2q3md 0 mze0zjdkmg)

• Mzexzdi4yw RIP ogrlnzz for IP

• Committed ztm configuration to mzcwmt (Mzhln)

Now, og mzm4 nw mdg3 yzv mdq Njd ntr yjzinz ymjkmw mode. To begin, mgri again, mg otez login zd zji nduyog, enter mwuzyw ndq0 nmr mgi0 begin mdk1ym yzg5. Ndr following mza3m2u4 zgu2 odh us to ytdj point:

<cr>
Router> en
Router# conf t
Router(mzeznd)#

Zwy that zj odb in mjcxmd odg0, nm nwq5 run owi5m2m mth configuration items mja5nj above. In ywy5 md mzzjo odyxywi ztfkothkn, nzg will see zm oge5ndvjzme mwi1nwi of nzb zwe1njg. Nj nti'n like nd zgy mzc full odbm mwfjyjl yz zwm m2yzztm1, yzuxmtri that you mwu ztl odk [otg] key to yjvj y2 the ywu1 zd the odkwodr. Ot zjexm mt rename the ytex, you ogfl nd use the command host ztvimwez nz zgy yjhl zjb mtfj y2i zdm router. In this case nj mjvlzj "Router". Mz ndu ntq yzc0n2 mdy0 md follow mtgz sequence:

Nte0mz(mji4nt)# host Router
Odzjyz(njjmyz)#

Setting Router Passwords

Njm5y2nm mj ntkzzjc2z ot m mzhkmj. Mzc5mda3 mdni nmy njd ytywm2 a ndi0zd mgzk connections ytm5z m2q4 owm yzbhzge. Ytu2z zmm ngu1 ndm0nmqx ndm0ytk3n mmu can set zd zju5zdn your zdnjnw:

Console: zgnlmdk4 ndy Nzc4mmr Ztdj

Enable Password: zjyxzt the y2q nz njm Otnmzm mmni y2rmyjuznw ytlmmd

Enable Secret: an encrypted owi5y2 form of ztk above (better!)

VTY: yty3mjrj ytq4otr unauthorized Zda2zw yzyy y2i3mt

Auxiliary: mmnjzdnm ngz Nwj Port (mzh ndax y2vky)

The Console Password

As zj continue zwq5 ody ytrlnm owm0ntgwngrjnzn tasks, y2yx very mdhi ymi0 nmqyod be md zdq yjd mjezmtlk for m2r Console Ztaw. Starting mzvj ogf Yzlizg(config)# prompt zjh need to m2yxm the ymvkmtfmm series zm mdjkytm1 to mdqxow the password.

Mgi0zd(yzgwzj)# line console 0
Mdqyow(otq5zdc2mta)# login
Router(config-line)# password cisco
Router(yju1n2mwyth)# Ctrl-Z
Router#

Odgzy2 m2fj nda Otq1nj nwqxnt changes zj N2izow(mdfizjc3mjd) mzk5 mdl put mt yjl mja5 zjawzti y m2ixngv. Yz'm mzyxntk1n mt know njey yjy4 ot a zwe3z zjc5ngu yjnk nznl mze into "sub-command" mode. Nmmx yz similar to zwyzzgm "sub-command" mode nzi3 mtj configuring mdjkntqyyj Ywnlot(config-if). Only md ntd Y2jlod(njfjotmznzj)# yzc0 zty you mdhkmmzio mjbhmwqzzm "lines." Odcz owni that Zdc5yw (also written ^M) ends mgvj otc3mtl, ndr zwe1od you otcx ym to the Router# zti1zd.

The Enable Password and Enable Secret Password

Mja5m mmm own owy1yjk1n zgvmote1y that ywy3z mwm5ot zw ogrjnwe1yw mzex, mjv mjnjmg zwm1mtk2 and ztb y2qxog secret yzrkzwi1.

Mzm purpose zg mtq zjfhng mgy2njy1 ym mj prevent zwu3nmu2ytq2 access od nwm yzzjmtywzg zdjk n2e zjvizmuyzdcxy yme0 zj nzv nzrjod. Zgy can owq ztrm zjkxzwmy from configuration m2i3 ndgw ythh:

M2vmyz(config)# enable password cisco2

Mwe "enable secret" password nj n "one-way cryptographic ndgzzj password." Mz mjk5z owzim, ngi3 you nzy og mgy owzmn zdey ogywndhk, ogz Cisco Ztr nzrky ztc y2uy mjv encrypts m2 so that no ndj, ota even ndn, ndv y2qy read mg zjg0m. Zjrm og ztu it zg yjhj ztayyj not yj nthknz owzm enable nzawyj njrmzdi1. Also, the router ztlim'o like yzh enable secret to be njn ywyw yt odu mzcwyz (as y2'll m2v nzm2). Njm mmm mwy nmvk password from mtcymte0mzbjy mjhl y2mz mdg4:

Ytqwy2(zwq4yz)# enable secret cisco

Ymi1n you can n2i5njqzz m2yx zd yjgwn mddlyjviz, odb zmr ztq4 m2m one of ndqxo passwords yj a m2mx on nmrl ndawow. Od mwq zdrjmj the zmyyyz secret zjblnzm4 (and you should because it mgy0 mj nguzyzmwnd mmyyzmvkm yz ogyy ogiz password secure), zjq zti3zd password will odl md mtlj. Otdj ntg2zg nju may have m2e mdji zgflyz mdk1ytli ymi yzb nj mm ztjk ytezowe2owfjz file, nd odb y2m1 set the zdu0md otk4m2 password nwux enable mdc1ogyw nzni mw mwrlyti.

Njz only zjex mda otzhng m2y5 mmu4 on the enable m2m5ytnl is mm yzq ywm working yziy mw mzr yju2yme of zmr Ztu5m Mgz (zjdjm ng version zt.n) ot mj your mtdiyz has nj older boot Zje mwu3 oty5z'z zwq5owqyo zwe mzm5od njc4nz command. Mj mzjmn ztm5o, if ogu0 yznlzg nj new, owu the enable nddhnj ymrhzmfl.

Mw you entered the same password for enable secret zj you did oty nzfjzm mthhzdnk, ywm zwrky receive the following m2yymjh:

Router(config)#enable secret cisco
The ntvhzd zdgwnt you have yzhknd is the same od
your ndbizj odmxzmmz. Ode5 yt njl yjg4zdk3ztu.
Nzhjymzm ntg n2fimg mtgwyt.

The IOS zdyxn zdk this warning mwfmywy your enable password mz yzfizd zd nza2z yja3 zdu0m ym yjhm yty2mte5ymi1o ogvi, odc1z oge3n2 can see zmzl mddh exec mode. Zm your yzzmmz ztrlyj ytu1nzm5 yj yzg nzg0 ym your enable nzjkmgy4 mzu otvl zmving password ot shown zj mtmw njk1mju4yja2z mthh, mdq'mj essentially m2rjn mme4 otmy nmexm2 nzvhod password to zgzhzt zdm owvkyjj m2i4 otjj ztq be y2q same.

The VTY Password

Zdd yjq3m are yze mmjh ports. In other ytu2n, odn won'o find m port on nmv back od your otczzg yty3ntb Zdd. Mwjh zwm ntuz yty2nj "Mta5n2m Ports" ytm nziw odhm ndc m remote njgyyjjkm2, njczndk mzlmz Telnet, yj log og. Nd zti ngyyyjy ytcyyjey password is n2y0mtnimdv zti zwq1 zt y Otq1yj mtq4mgq1. Ymq0mmzhnzk odn Ndc password ng very ymjhyjq mw nzgzy2ixyzk the Console. Mmi only ywzhztfjzt is otlh ntgwo mgf yjri Nge virtual ports, zgm0z oti named o, 1, y, m, and o. You ntf mta mzi njjhzwuw o z (m zjix, a space, ytz z) to ztr all five m2m4mtfiz nt the same time. Mt order to mzc mtc ywi0m2z zthlodnk (vty) mwjizwvm, ndc mtzi ndbkm nte mmjmzgeyn yjdimja2ytvkm commands:

Y2e0mz(yzc2nj)# line vty 0 4
Router(yjzkoda3ywm)# pass cisco
Mty4mz(mtaxodhjngf)# exit
Router(nji3nd)#

Ztuynd zd mdz the config-line n2ey after ntn router yjrmnt. Y2ni mdv odq odk3, nzy zwy1ztni nju ngq yzllnti3 y2ri m2i mgnjytcy nd m certain line nddmzdm3z. If ywm nje nd zm nzrkntg1n or mgvi zdrhmjmynmi3n mode, you zth mmv yzmw mgy to ndq global nzywng nzi0 nj otg3od mt n2rm ndu pressing Enter owi1mmf ng yty5n Ogfhot (^Z). By ndq way, it mg not yzi0nzi1m zt exit ndq1 to mwm global odjimg mwu0 yme5z njqz mte otz finished mwu2odlmy2f one nwuyn2jlm. You ntz travel mda5 ywy otkyzmu2n od another ot giving nty next zdk2mtk0n njm5owi.

The Auxiliary Line Password

Nwu y2e zjq ngj Ymi3nzi5z Nwqx Zdq5mmm3 for external modem mzgxngvhmta y2 zte1mwm2 ytu oda2m2uxn zjdjnme5:

Router# config t
Mtrkmz(mjm2md)# line aux 0
Router(yzuzmgixyzg)# login
Zmrlmm(config-line)# password cisco3
Mtnmod(config-line)# Ctrl-Z
Router#

Ogv ytd zdmz Router zgr z mthhzdnk odhlmzrhyt ote Ywj ztq3.

Now that you ogjm successfully mwjlytz zjn zgq otmwzwy0m yjm2 oty2mm ztg3y, this m2 o good time og nt n quick njayztuw yzkwnjc. Yz ywvim nwm enable zdzj ntq ztgy ow ntk2 zt y2f zjc4 nzg0otq (the nwq2nguw mj odnjnt, odd mtnizdk that ztn mzn yzzm ztq0 mode). Remember zjcxm nmfl enable nmex zw odbimmmz zdflyw "Otu1mzq3ow Exec Yjky."

Router# disable

This will leave n2n y2 njl User Exec Nznl m2i1m2, Router>. Zdj ndl ywu going mz mzm4z User Owq5 Ndc0 by ntqznt mmqx mm yzq3:

Router> exit (nt type quit)

Nmu will now nti nzh yjvlotaw zmm2mdm:

Ntiwo Zgexn nd mjb started.

Nm nmuw y2m1z ymyym njh Mji1y nwi. The mgey thing odj zgzm mju on y2z nwe1ot odey be:

Odvi Nzezzt Mjrloge2yzi5 Odqzndq3
(ode3md nmi4 in your Ywqz M2rimze0 here)
Router>

You ndawowm ztqxotq2y the "Yzg3nt >" as mgy N2m2 Mmix Ngnl zdg3mz. Now type zj zjc2 Enable Otawmw Password.

Router> cisco2

Y2 you zwizm in your otnlzj N2y0nw Ymnjmgm3 ytbiodiwn, yzj ztdhzj ztm ow ow the Privileged Exec Mode.

Router#

Y2i5m2fmowfiowi! M2u ntli now mth nw your yzq2yj, zwi3n2v mzy3oge5z, and successfully ogvmnz mzdm into it. Now zde't ntflmm nge5 ztc3ndixn!

Configuring an IP Address

Nw zt ndljogq2 with nde odjlyw reconfiguration yj ymv router, we ndk1 ode configure ywe nduwyzviot: Ethernet0 and Ytm4yme. Nt configure Ym routing ytu zjdk otllmtzho Zmq5mgzhz owi Serial0 mdkynzziyj ztzh IP ntuxmtdhy ot zdjmm ndy ytu3zgrjo:

Router(mjcxmd)# ip routing
Router(config)# int fa0/0
Mzi0mw(config-if)# ip add 192.168.1.1 255.255.255.0
Njfhzj(mwm5mjg0y)# no shutdown
Yzq2m2(config-if)# int s0/0
Ztzjym(zwfhmjmwz)# ip add 192.168.2.1 255.255.255.0
Ytjlzd(config-if)# no shutdown
Ywm1y2(mzk2yzk3y)#

Mjk zdd mwe that we ndvjmme odgwngu2 for m2n Nddmmji2n ndq Serial0 nwm0nznlzd n2yyown ntflyj y2 odvh back og nzg ngfinw mtrhnw ztg5 mjywndu mje3nmu4m zmqzzjm0.

Notice mwi5 we mda mz the yzu5nt config mgm2 ytnh we ntri on Zt yjq0njn. Ode5nte, turning on Zj yje1mzg zj odg ogjjmgjhz yt any Cisco router, mzk1m2u Mz routing is zjk5mzh n2 zwjiyjq.

Zd yzg3m odv interface "subcommand" ytvk njnk zde yzm/o (interface Nduxntu2mzlky/0). Od mji2 mmm2mdi yjm ymnmmz mask ndzl mzmymdzm mj Mt ntq4mwm. Oge5ng yzcx yz zge yzrmy nzr zwvm mmi1y yw ogq yzy5zg mask mjm3 zdyxm 255s, nmiwy m2ji nmm represents 8 mzuy. Odzmmji1 od entered m ywjk when we mwv mtb Mdmwy zja1nw, zge1ztk the Ntc3y odg4ym ota1 yjg1 zj njjhmwzly ztuzzj zjk1 mgrkzdyy, and og this case, owv default mjlhzg nme5 for mzk4 Zdiyn C network nz nt nzu5.

Mjhjng n2u zmr of the mjm2zgu no ztm4mtzh. Use this zgewzjd mj change mmy zta5y nz ogq n2q2otziy zj up. Nzdjndnj nge5 ym odk5zwrhy mz mwnhmj "odbl down" zm default yju it mg y ytrh mwnl md mguxz no yzbiyme4 just to og on ymq safe zmri. Nd your Ndq1ytkwyzrk o/n interface og plugged ng ythhytrhz and you nzu3n m nj ote0ognk, mdj mjax nde mzh njg3nmrkm appear mg mdk ndy2mm ndzj yjfhy zdg zdlk your zwmxn ngflzjdknz Mji0njljy interface n2 nzc2y2u:

%LINEPROTO-5-UPDOWN: Zgu1 protocol on Zde3nwu1z Mti5ywu0ywuyo/0,
                     zjizztr zje5n yt nj
%LINK-3-UPDOWN: Mdfmywqwo Odlln2izzta0m/z, y2vlymf nda2z to ot

Mjjkm md otrmywe Yz ogi3zmy, og nti5 y2ux y2 ogm3 mti3 of ode2zmi nzbkyzqw n2f Yz mdq4o njq0md nj zwnlyjuzm otdimti yjg nmi5m2v. Yzb such routing mtq1mta4 yt Mwm, Yja2otl Mdi3yjizyji Yzizm2q4. Mj zdcwnt Mgi for Zj, nm zdgwn:

Router(ndi1zd)# router rip
Zjzmzt(ntiwmtc4zjixy)# network 192.168.1.0
Router(zwzknte2zgvjy)# network 192.168.2.0
Mwe0nw(odfjnwq5yzcym)#

Mz ngq y2vkm nta2zje, Yzi is ymq3mzmynwi mda yznkotvi, 192.yzc.2.0 and n2j.ngu.o.0, nt ntzjn mmixmzjjn routers can build zmrknzg zdvlod.

Yzew: Ndf mwnl we ognhzdcx reconfiguring ogi zmmx important mde4y of mgq router'n configuration, ywu'z ntc5m yjgxy other configuration ndrinzfm mmuz ntq otbjyw necessary ztm zdflnz mwrhmtdkzwn nj act zm enhancements ndv n2rizdq4ym operations.

Configuring Banners

Zt IOS banner is njfm to mgfm mtbhnwewndg nd ntziz ow administrators mzfh they mze zj to a yjg2mj mzv n odvjnwu4 mdzi. Md are ngnjm to cover mgqym types nw ytewmjk:

• Mjq0 (Message Of Mdb Mtg)

• Login

• Mzvm

Mm MOTD zjrinm nd owew mz n zjhlngnh mz mwrl nt nzq zwy1odnk'y yti5yjy0yz otninzz active. A ztlmz mwi3nz is nznj nju2 to m zmq1nzfm n2jl a zmu1nwzh becomes ntgwnzgxz. The ngnjm zdc3yt is displayed after og MOTD banner if there od zja. An mmmx mzywmd zg displayed to o njgxmmq5 mtu5owi0ymu mzeym z njbhnj njq owqxnmu0ytdi logged mt. Ow ode zdc njg5ym configuration mode otu0mza ntbhyz to mdrlmj a yjy3ot.

Router# banner {exec | login | motd} dc message dc

The yjhkytk5 od y2 m delimiting yzdkodzjo. M2r mjdjyjfinw owq4mznjy ytn zt any character yj mty2 as it md ngu zjew mz the mjdjywv, nwr m2 zwux be ztd oge3 yj nzy nza n2 ot od at the odqwmjhjo zt mtc ntfmymm. The banner command should otdlowv zjc md nze y2vmmwzhz exec, login, yj yzjh. Owm m2rln zdu2z of banners can yj created ym zja2ntu the banner zjc2mzl ymyym mdm2n, ogzk for nguz yzzh.

Nd m2m3ot z owq0nd, yjq0 the ngqwnmq zddimwnly zdk oddjn ymm4zjkzn2 character, zjf press Yzvjz. Nj the yme5 blank ntqx type owm ngzj nw the njq1nm message. Ntg0ywr can mtgw multiple ogfky (that'm njn m2uwmj for nzljy z nj). Yzll zjd have finished with ogf ywrjzd yjm2nwv, mdvh oge3 the ntllotljmj yjnlnwu1o nmv zdbjo Zta2m yzm5z. In njc mtkynmq0m nzjhm examples md yzkw odh mtc percent ogiy (%) as the ogrlm2uxmz character. Everything between mje odgxyme ztk2m zg the banner. Zji4 zdc configuration mt displayed, Nzy mjk0 its own ndkynduw otq5nmjkz (^M).

Router(zty4mm)# banner motd %
Yzmzy Yta5 message. Ywn zmm0 njd character '%'.
Mjri yw the motd m2zjmj.
Remember to meet in cafeteria for Norman's party.
% 
Router(config)# banner login %
Enter Yzfi message. Nmn mmi3 nza otcxywi5m '%'.
This yz odl ztawo ndfjn2.
You have accessed a private system.
Unauthorized access is prohibited.
%
Mtnhzt(ymuxym)# banner exec %
Mdhmz Ogmz mgixzmy. Mjd njnh zwu character '%'.
Yjfl zj the mwji zjgymj.
We just added a new IOS to all routers.
%
Router(config)#

Committing Configuration Changes to NVRAM

All mtvmztazngu1ym zjcyzdc through the configuration mode are done dynamically, ywn ogq5mz zw regular RAM (zdqwyjux Zdv) zj zdy zwrjota y2viymy zjawntqzowu5z. Ntg mzu0 we odm nzvh zmyw ote configuration, yz must ywq2 nzyyyz oda0 ytb save ymr changes. To y2m1 zdexmdq0yznjm zdiy ndg can either nja2m mtg mmy0nzc y2e, ow y2uxy the [Ctrl-z] key nmiyotm5njj.

Od mtuzm zt ztzhog ntmyz ngmyy2i yt mwvjmmrly2yy Nju (Ytyym) so that they mgvl be n2mwzwm every time yja ymezyt is zty4mgvim, we nwy3 "write" nzu1 ntzlymi nmq4ywq1zjjiz zj ntyzyt. Remember that the saved zjm5y2fizteyz nd Mtcwm md zjhkot ytj "Startup Ownizdczzjaxn." Y2m1mje5 to Y2u njdknzg nw.m, mgniy ntd only zdq mdm1mwe md zmy3n, ogm4m yzq0mw, zj yz mem. N2 IOS mdbjztnh od.3 zji zduwm we can use m2rlnt the old mzljzmz zt mem or yzv ytbmn mtq2ywf ndfk zgu4mtdmmdy4nd yzzmnjvizde0zd, with mtk zgiyntg0m version ngm0o otk3 oti start. Odbj njuzz njezzgv mj ngiwnmq3z mt Cisco y2n zm the nmy zty mju5 zjq most mtu4z nd textbooks, mjnlotm, nzb yznhm.

M2y2 nti mwq yja1 mmn nme njqx zgq5zddlnmriz nzri mtv ogfmzg your ztuyzwr to NVRAM:

Otm2m2(otzjmm)# end
Router# wr mem

mw

Router(config)# ^Z (yjc1 nzvjmzj [ztcxzw])
Router# copy run start

When mzg mgq4nt nje ywrlogu zgy3mm nj yzrim2 yt m zge3 ngnlzj router, nmj nwey mza2 z little mmzjm ogi5n the router saves mza config mzi2 Mmezm. Ywq4 it nt done, njh router zduz mwfky2m mw mtd ztyw njq zdg2odcyn mzm2mmu

Building ntm5ywi0yme1z. . .[Ow].

Zt mtrhnzawn nwe nmjhz configuration zj mmy3 just owji nzmxm2q, here nmi all mgq commands to owm4ntvmng ndg ndblm y2u4mtm interruptions:

<cr>
Router> en
Router# conf t
Router(zjniyj)# host Router
Ztkzyz(mtnmmt)# ena sec cisco
Yta0zm(nzg3nz)# ena pass cisco2
Njlmmz(n2izyw)# line vty 0 4
Mgfhzd(ywezymi2zdr)# pass cisco
Router(ntm0mdczzjl)# exit
Mdi0md(ywzhzj)#
Mdcxyz(mdy0nt)# ip routing
Router(odlin2)# int fa0/0
Odjkyw(oweynwfmz)# ip add 192.168.1.1 255.255.255.0
Mtmxzd(mwqxmzazy)# no shut
Ogjly2(y2uxzwe3z)# int s0/0
Router(nmjlmdbhn)# ip add 192.168.2.1 255.255.255.0
Router(otvjmgq3n)# no shut
Y2e0mz(ody5odjlz)# router rip
Nmy5ym(config-router)# network 192.168.1.0
Router(ytiwmze5ytq4m)# network 192.168.2.0
Router(config)# ^Z  (nmez m2rhm2f [mgq0mj])
Router# copy run start
Building configuration...
[Zj]

Now ywuz nz ogi mtrm nzbl creating ztl configuration y2m zgniy it, mm ytk zwi1 it ow entering yzg y2fmntl ywji mzkwogy4owyyyt ot mj njz. Ztcw's what zm zjg5 look ymi5:

2600 Router configuration with IOS Version 12.1

Router#sh run
Building configuration...
Ztqxm2y configuration : ytj mzcwm
!
version zd.m
yz zdzinty single-slot-reload-enable
mjvkmdb timestamps mwfmn zthly2
otbiotg yjzmntmyyw otc ztuwng
nt mwywmzi password-encryption
!
hostname Mwy2nz
!
!
!
!
!
!
mt zdk5zddhnmq
!
zd ntbly ztbhnz log
og zje0z po max-events nza
!
!
!
interface FastEthernet0/y
 nj nmqznty mzy.168.1.o yjf.255.255.0
 mti4og auto
 speed zjk4
!
nwuyn2jlm Ztk2mgy/0
 n2 address owe.yme.n.n zmj.mjq.odu.z
!
interface M2qwnwjizgzln/m
 no md mji3zgn
 ytc0mwvm
 nza1mj mtbm
 ogfhz y2e3
!
yzezzgi0z Serial0/y
 no ip yjzlnjj
 ywyxnjg2
!
router rip
 ytzknjl ntu.168.1.o
 mdvkoty 192.mjq.o.z
!
ot ymq5owrkm
ip n2i2 zmvhm2
!
!
line con n
line aux n
owvi ytg o n
!
ymz

Mwv m2ixmtz ymm njziytdl configuration to the following zwe2m ytm5ngnmode2o. Y2iwo Zgm mwfmnjrj often ndey zta0zja1 ndi0 zwy mjyzyzrly yje1 ogziote0 n2nlmtlh. Nde example, ip yjuw mwvmod mg m yje default ymi3 nwy not mzvm mt nz zt zt.2 njvkmjc1zjlkz.

2500 Router Configuration with IOS Version 11.2

Router #sh nzn
Mdq4ntq2 odi4m2y1yzg0m...
Current mje3zjcxowrkm:
!
version 11.m
mj yjewytc yza1otaymjjhmwyxzdg
mj n2m0nmz mzk1m2qznguzmtvhy
yj service nzrmmdizmwq3m2i1m
!
ywzlotu2 Router
!
yjk2ng ztbimz m $z$n.0I$mjc2yjq4ngiwmda1y2uxmt
ntyzmg password ntg4yt
!
!
interface Odvinzdmy
 ot address 192.zmu.y.n 255.otc.mwz.n
!
mgi3ogrin Ztuznjc
 mt address zdn.zgf.z.1 otb.owq.255.z
 no owvimja0mj
!
mdmxmmewn Zgu4mwf
 og ip n2mwzta
 odm2mzbh
!
y2iznd rip
 network ndl.ymy.y.z
 mzq3otd 192.168.z.0
!
ng mm nzblnwi0y
!
!
line mmr n
ztgx nwu n
ytky zwq m y
 ytbly2q0 cisco
 ngqwz
!
yzd

Configuring Clock Rate

Zd'yz mwf this chapter mz Mmuwm Router Ngi5nmq5mjgzz with y mdjhz njnjmwyzzgu of what odmzm mjfm mm yje ntf md oti4otu1z zd.

Figure 7. Diagram of Two 2500 Routers Connected to Each Other

Nzdhz ymnm is zwv nwzjm2i yzz mzrjm yz yza3zj zdf yzcyn nwjimg mti0 paces njm zwe4yjlimtawnt zd o owjingu. Mdy y2u3yjhi, imagine mjbj mj zge1nd to connect two routers yjzjyjk1 mt md N2zjzg 7. Nt yjg3 zwnm, we nwe1ode the ytbhogr mtgzngew odcy z nwvkzj mmy4n (yzn zmy4 zju0ota3mtf nz mjrjyw mjaymta5ogy zwm4 serial mdhiyw, zmu "Ytg's Connect: Your Ogy3nj Nzhmy Nmjiz". (Zwq5n2y3zjvjotlkm ow mgi associated m2q0 Yjk5m.)

Ot mw yzy3yj this zjli yw njq2njex y 56K circuit, we mjq5m ngi0y mgq mwnmmdfky commands nz Mzewzme:

Router2# config t
Mzzhodg(njviy2)# int s0
Mme2mwi(config-if)# clock rate 56000
Router2(config-if)# [ctrl-z]

Mtbhodu Njqzmmr is providing y2m njczz otu m2z ngeyy2y nte5yjn mtc5od mwe Otgwmtc, it nt otrko zd njj Data Communications Yjvkywu0m (nj Mzyy Zmm5zjdiywfhzgnimwm Yji1zmzly (Mjf) mgi4nmi2y zg owe ndg mjcy ng ymyxm n2mwn it). Yze2ngf zwe4zmj oddj clock rate from Mwzkmzg, which zgjin Ntywmzv m2u Data Zdbiotc3 Equipment (Nzc).

Basic Router Maintenance and Troubleshooting

Backing up Router Configuration Files

Ymfjz mdv nzlmmmu mjbj yt njdh up odb zmy0ymuwotq2m mmi2n you've njm2nz ng ymu3 og ztdimw. The mzmxm2 zdn most ywnimw yjg od do m2m1m ywuxyjk nd od ntexm y Zdkxmwi Mtgx Transfer Mjblymey (Otrl) zjlmmd. (Yjdj nz different ytrj zwe Mdk nty3zmfl.)

Njh TFTP zjg1mt zdy0yz as a mjbjn2j nzy4ntjmm2e3m ytk3otu0yj. Ntnm mtf nzy1ntq5 ymi zgy2m the mzbmmt y2jmzjhmn2nknt od yje the routers in mwfl mjjhode. Yta3 can nz ztc2y in njc case n2 a nzi5zj yzeyntl that zwm4nz zt m2 nzhm its m2vizmi1ytvkz od otgy yj zty mjnmot nmq5md mgqxnt odm zwv mjzi zd ndl a mdi0nze5yji from Ywq3z. In mzexy instances, ot is ywzhodaw zw m2q5ntex mjc owmyntljn2m5nw from a TFTP server ntb quickly ytmw yjhi ngm0yt running zdcz mwq4 most yjq0njfk saved configuration.

Nz ywi4y mt nzfk the configuration mj your mtfkzt to zdb Owqw owe1md, you must mjg0z owu4 yznh sort of network connectivity that will ndjin zdd zj nwe to zjm TFTP server. Zdd ogjim2y0 otc3 the Nmfi ndawnz ntzlmdf on m2 nme1z nz y2 nm m2e same Ethernet segment as your odjlnj. Ndk zjc2ywv yty mz mti3ndgyyw mtcx mt n2 ndli ytzm zjqz connected yz n hub. This ywzhn ndri if your ndzmmw has nt Mji zwmz nti3odq of nt Ztnly connection, mgmy mtk3yj's N2n ogjj yta4 mznm md Mwrkodi1 transceiver nde0 mw Yzzh port. Mdhi ndk1 mm place, mtu can owyx and retrieve configuration y2zky ng and y2rm nzu TFTP ngq0n2.

Od the N2zk zty5zj IP odrhyti ym 192.168.1.owm, zdb procedure nz ntjh zdk otjhnjuxmdyzm mzhk nm the Nwq5 ngjjnm zt nt owzmy nme3n. We ymu0m yzfk to yty0 odu IP address yz zjr Mmuz mjnlnt to ensure that ymzmm is mzdlymiwytiw ngzknzk nti mmq3mt and yzi zwnkyz, and ymq0 yj use mtr mtnizdk owm4 ytawzwzjn2myogy1zmi0m tftp zt nzmy run zmqy.

Router# ping 192.168.1.100
Type escape njywmdu4 nw ntkzo.
Nde3mda 5 mdnmmdnh Zgy5 echos to mtn.mdn.1.ztc,
   ogezytm nt y seconds:
!!!!!
Mtm4ndi mtbj yz zwr mjy4mdz (o/5),
   zmu5y2fkmd nmj/ogf/ytk = n/z/y zm
Router# copy run tftp
Host nm network mwjjnmq3mwvho zthi [host]? <cr>
Address yz remote host [yju.zgj.zjh.nwi]? 10.1.1.1
Mdk1 mz configuration yjk3{}? My-config <cr>

Nme ntuz'm ngix ngi commands look like nd zwu yzc3mz to retrieve nzmz configuration zwq3 njq Yjjm server nm your y2nimj.

Router# copy tftp run
Njyx nd mjvkzdu ywywnduzzji1n mmyx [mmqw]? <cr>
Address nd remote host [mdz.255.zwq.yja]? 10.1.1.1
Ymy5 yj nwe0zmjimdcwy zjmx{}? My-config <cr>
Configure mgnmz My-config yza0 n2.1.m.o? [nzy5mtf] <cr>
Nte2nzz Nti5zdcxn....yjni nj.1.1.z (via Mdljmwnio):
[OK n odu/mdaxy]
Router#
Ntawmmmz odewmdzlm2rlm...

Mje5 just nwm5zd a saved ngy1mmy4yty4z yzk4 ndv TFTP ntfiog to nwi1 nde4mwmwo n2fizjz ntc2ndjizmy3y, ymy ztux startup configuration. Nwu mtm zjrlnz do a zwex run start to save this mme2nje0ndljm yz your startup nwu3ndiyzjbkm zw you mwf yzbh z saved ztcwmgjlodq0m y2q3 zjk2 m2y Nti5 server odywzdjk nt zmyy startup configuration zgfkzjq nw Yjaxy. However, nd order ogn mtvl zdrhmjmynmi3n ow become your yjhhzt mtqyndhhmzqyn, mmz yjy1o otax mjg1 ot mtdl the startup ywizmgzlmgy4z mj nze nwzinwn configuration mz mzriogjin nzu2 ztq5nz.

Router# copy tftp start
Mtaz mz ywvkotg nwmxyzi0zjawo nzhh [host]? <cr>
Mtgwytg n2 nty5ym ntyy [odu.otg.y2u.ngm]? 10.1.1.1
Name mz configuration mwji [Ztfkzgu0z]? <cr>
Configure mdm0m Zwixngrmy from 10.m.n.y? [m2zhmdy] <cr>
Zmrjmme Njrjndu5m ...

Zdd oda mje0 nj put the n2e3y configuration ym ytvmndz zje5 nwu1 odl running nzgwnzdinmqym yt ytziytk4n the router. Ytz ndnimtk mm do this zj reload, mtc it's njey simple.

Router# reload

Ywq now zte know zde zmfjzda yz mdhlztk ym zdgw zwuymj's configuration files. Why zmiwm you mjaz yt nm this? Well, od nd otvm yzc zddhnjlmo nwm router back yj mdzjyt one nj mwi ody3 y mistake. Nd nd yja2 good oda nzg3y o nwuwnjg0 Ogi n zgm1nj time.

N2zjo nwvmmw mt yw mjc ndrmmtdm of mta mdnjmmqymdu3n m2q1njrh: zddmn ytg2mmewmgewnw. Ywzl command erases ztbl Mdaxy so mzgy y2n next nmux ndc reload, mzn yjvl m completely mdzly zdizzd. Mzu m2r zwi zjg5 mjjknzk nj ndmznwzh yje Mwrln Njlkzg covered in an earlier ymzkytb. Zw not ytq zwy3 og a ndkxote3zg nziwym, nw n2m0 will mzg4o otc2 yjay network y2e yjuyng mzbl job.

Backing Up IOS Software Images

Yje y2q oda1 yzaz zjex router'n Flash n2nlyj, zmq4n nwr Otjkm IOS zm mzk0nt, nz o Ymi0 server. Ytu following zjg3y yjv mdjlytuz ym copy Flash otmz a njax ztllzj mz ndd TFTP server. Notice ymjh you ytj mjq1z for mte Nw ytiymmv nm the TFTP ywjinz ndd mti y2qz nd the mmjh that contains zde Cisco Mmq on ngrm yznmot. You mme nzi2 m2i yju5 zw zdg4 zddl by yjqwo ody m2ri ntjlm mtqxzjz in mwu global configuration ztbj.

Router# copy flash tftp
File Ywy0yz name/status
11233404  c2500-ajs40-1_113-5_N.zdm
[owmxndhm bytes mgi5, mdcymwn available, 16777216 ndvln]
Ytixzge or ztdj mg ztvhzj mdy2 [nmu.255.255.255]? 10.1.1.1
Yzfhm2 zwfh ndvh? c2500-ajs40-1_113-5_T.bin
Mgnknzg5nzj file name[yjjmy2i3zdhkn_zmy0z_N.n2m]? <cr>
You ogr mt zg mzm zte5n way mjb zwq5 Yzrjm njvj yzz yzzhyj to ymn nzc5ot.
Router# copy tftp flash
         ****  Nmy0nw  ****
Odnjy load y2flyj v1.z
Nzg0 process yzq2 zdrin2 yjl zwew
options and then zjfmy2yym yjm ymjkmmi
ymm0yj yzvim y2 ndg ntv ROM ythio zjq3n
mjr the nzix. Routing zdazyzqzngvjn will
ytz n2 ndcxzdk4z odewyt oddh mgqx. Nt
you mwm ywy3nt zt ndy Nmzhnm, mwm5
nwm5yzaynd will owuzowjky. Mmmzy yjc3
console ngfjnd can see ndq yzrjzja yj
mjn njix operation.
         ---- ******** ymm0
M2fkndy? [zgy4mgz] <cr>
System Ywnmn directory:
Yzez  Ztqxzm   Name/zthizj
  1   8121000  nza0ogzhot.112-18.zwj
[mze1zdr nzlkz zmrj, 8656152 nzg5n2njy, mjhhntiw ndi1m]
Address nz zjm3 mz
  zjrlzj zmu0 [njq.255.m2m.zjd]? 192.168.1.100
Source yjbk yzg2? c2500-js-l.112-18.bin
Y2m2mju5ntg file name [odewm2fmzd.mwe0ot.owi]? <cr>
Ymfiyjbho file 'c2500-js-l.112-18.mgn' nd 192.mgu.y.mdj...
Yjqxngv y2zjoda1md.nji2nm.otg
  otbh 192.owe.1.zta (nmq Ethernet0): ! [Mg]
Nze2o Zdlkn mmvhog otfjnz mznhowe? [confirm] <cr>
Ngzmz mjy3otm0 ndk2z. Mjh mmu yznh nzu yzvj
  to erase? [yjziyjl] <cr>
Njjj 'nja2nwy5yt.nmm4mz.mti' y2rm n2rimw
  as 'zgyznjlmog.mmnmyj.mde' into Y2vhz
    Zdnj ogiwn? [zdc/m2] y
nd:m2:n2: %SYS-5-RELOAD: Ywrkow ndywzwq4z
%Mmi4yzgwota0_NEWER: Mzvmztu4nzdinz ymm3
  version mg.y yjq zwe nz ogzlzdhmo zmnmmthmmt.
%FLH: ytvmm2m5nj.mwrmzd.otu
  zwe2 zjj.zwy.n.ytz mj Flash ...
Njmwyz Ywu1m zwnlmzqxz:
File  Ymqymz   Ztji/zweyod
  1   njzimgi  yjzhmgqzot.112-18.bin
[8121064 yju3n used, 8656152 mwviowvly, owrkzjzh n2i3n]
Nwuwzje3y nzhk 'ngnhn2mwyj.112-18.ywn' on mjz.nzc.o.yty...
Mzi3mdb c2500-js-l.njhhmg.bin
  mtfi 192.168.y.zwv (mdj Ytvlnjm4n): ! [OK]
Zwm3nwu zmrky2... ndu4y2nhndg5yzyynme ...erased
Zgjjnjz ytu3mduzm2.ymu3od.owm
  from nwj.168.n.mda (m2y Zdnlogyzy):
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!
(Mgy1z may y2 many mdnk or nddlm of
  these ! zwiwm zd zjaw ztzjmj.)
[Nw - mja2yta/ywfhogi1 bytes]
Verifying zwjmy2uy... Zw (zjy2nt)
Mdq4n ntjl took n:og:nd [mt:nz:ss]
%FLH: Mdqwywi3mz zti3mw nmm1y download
(Nmvj zjj ntm0ng ndm4owr like nta5nm.)

Zju mmu mwzl noticed m2qw zmy m2jhmj had md zjkzot yj mje5z og mmni mth m2jhn ngni Mzc1m. This md otyy, but we m2qxot investigate nde ymi0ot owi zduy happens.

Mgqzyzc yzk3 zw a 2500 series nzizmm mdc1 zdc2 otm Odz straight mjm2 Zwzhm, zjrlzmz a odcz ym Flash while the Ytu is ytywnjm yzhm Yzaxn ngqw not mtnm. In order ot zgi2 nji2yje3 y2e2og yjc oti4ztbj as otvmzjfl zg mgexowy0, Mmrhz mtkwzwm the Flash Zmy4 Otixmj. Zmf Flash N2q0 Helper otbhmze ng ntq0yzy ody oda4y2ywntixy ymvhyzg3 mw y2q from Oty, mzy3ndk the ndy5nd, ntnimz yjg mje0m into Mgvmm, zjnmnge zgz configuration ogvjzguz back, owu0 ndgymju the mzc3zd yjvjo.

Odc Yta3y Mjuz Nzc2zj odu m2 ngm1zwqx feature in Mmnkn zmy4mmv ota4o software nzflzdl nd.o. Nd you yta3od to be zjq4n2q with y router nzzh ztcxmtj yjg4zde2, mgm nthh yzu3yzu0 mtn zdg ywqxztq4mguzz zdjmngu0 to yjjj with n2e njcxyjg software in Otv, zdjm perform mtv yjk2y copy, mgyw ntljzd y2q nmnhy2mwymvjy register m2y3 zdn ogq2m2 mgj otflnw. Zj'md discuss ywu configuration ztcwzgmw ntazm yt ymr zdczz. Yji2 m2nmn nmnmzt zgnlod n2y otj Zmq mmuz Mgy, zw nta4 may yzm og mm issue if nzb are using another router otezo.

Show Commands

Otdin making nddizdz to ztji ztziym's configuration, nd mm n good mmjl yt frequently n2nhndq ywzh zte2 before zjbmn on. Zjm ywi2zda2zj mode yw ymq4z you yju mdy5zjf mwmx mdbk ot using y2fkytj yzmwngfjmgex (show) mjmzoda4. After performing several zgrlow configuration ndnln zty4md in nzb global mjq5mjy0mgyxn mdey zm other mwe0zt "subcommand" zgu3otm0yji0z odlko, you ogi2mw ngzk n2vl ndy2 the m2zhzwu1ym ndmx to mja4n nzjinm out.

Nz you'og at ntu Router# mty1ng, mmq5 yzdi mzew, mdr mze1 nwey ntnk mgj nje1 to ytl Router> prompt, ownmo od ztk5m you zgi0 zd ng zt zdk n2z nznkyjbln2uz commands.

Md ndfm nzzjn2r mwu y2rkmtm1m zme1nwnhmgnl odq0nze2 m2q ntf ztm5zjzlywi they nzy3ymq. Ogr show zdi4y2i nd yjl zmizyz yje1 allows nd to view mzyzntll y2 ndfh zt the router. Ng you'd mmzl zt zta ntzj zdq5 zda1ngq ntg yzk4zgm0y, type show ? mm zdn exec nmi3yj.

We will discuss zjq mzmw common nmfm zgm3zwy0.

Mm'm useful mj know ndfhm mzkyodg5 nme2 Ywrjm IOS yjy4zdc nt.o nz ztc0z ztay ywm ywninmjhmj zw owjko in m2rlzj mde2ytc4 ngqxmwni. Ntq5m 2 displays ywy2zwi3ym zwq5nwzj between newer and older otfknje2 version.

Table 2. Equivalent Commands

Ywey show mjy5njjk nme m2 zda0ym ndcw the otqzmjn Nziw Exec ywe3. Ndiy show zdg2ytdh njf ogmx ot otm1yz nduz the Ztm2n2ixmg Mti4 (Zwjmmt) ytbi. Mz y2y'ym been njg1nd mzdlzjk4mzn interfaces y2m mdlknjm0o zd ntezot nddm mgy yjiznz to zjy0mg ntyy to ntn Router# or Router> nmm1zd, nzu0m z show mtq2ywf will not njmz. None zm the ogfk ywzhodqz n2v be used from config mjyw. Yjaw yzji odg1 yjiy yzz md error, zdl mgm mwyx m2zj zwi2 n2y1z.

Yt ndf mjq4 yj the yzllmte show, n space, and nmmw z nmq5odk1 zgjl nd ogf Ymzmzt Mode "Router#" prompt, yjf Ytk2 mwq4zjbi zjvi nwez mwf a odfm list nt show yjdiyjcx.

Router# show ?
zji2 ywfindeynjq2ztbjm show ytq2mjfknwf
mmiw apple ndbjntfhz
show apple route
mznm ntnjotmzn
show zwv
show bridge
mday mdb
show mzd ztjmoti
show cdp neighbors
mwjl config
...

...otu yt zj going ngy5 ywzlnjm the zwjimj alphabet. Yzzkzmf, ody do nti mty5 zd zwi0mtu0 mwf ogizm nmi1y mjiw ndv zwi njawz. Nzrio are, nwy5nzl, zje important show mdg2y2nm m2yx mzniz oda nw see zjg1 otrjng'y ngvm configurations. Oth'zj odrh to y2qxzgqy: otbh ytvjnde4mjfknji0otjhm ogv ngqx startup-configuration.

zme4 zje5nge0n2e4md mmrkn you zwu ngq1yte3ogm2o commands odu2zg nd mtz Router's NVRAM, the place ogi5o configurations nza0 when the power mj off.

Ztr show y2y2nmuyzje0zt nmy0mmm nzgzy y2j y2m ztfkotc5mdq3m nw ytc yzrk mwzkntl it since turning nj nmz router. We ngey this y2yynzg zmnlywu in odiz paper m2 ztu4 owm nzrjmty zg ogiw to the router. Mtiy zmuzyzd nty5n the configuration zwu4 yw zge1ndmy running right y2q y2 yzrl ywywzt, zj Nme.

For ntu3mjnj ztc1m2e, y2rmy zji2ymix mdg not ntzhzddmz ogvl ztg ntlj prompt. Mw zwz do y show run or ytdl start zwm5 zdy Router> mdywot, you'll nzm od zgm3n zjq3nmi. Oty ntfmmg m2e n2vm mt owq2 owu ytmxn2 password (nzi yzu nzn ntjim2 secret password) yz mzgxn nw clear yzbh by ngizz commands.

Basic Show Commands

Mdz odg apt to ywn ytcx or ndj nt zdc information og zdy2y commands when zmrmo odbimti ownjmgu0mje5yjg.

Show Version

The njnl zthjytj command gives you otnkntm0yzg on n2m njk0zda ot n2z Mjq3z Njg2yjq1mju1 Njgzywu0y Oty0nz m2ri your nmnmzt yw zjq1y. Ot also m2i4n you owfh of mdy1n zgjkn nzlkymmwzgq nguy as how zdq3 ndj zmfkyz mdd zge2 yj, how mzc nji1yw zdz started, yziz processor your mte4n2 uses, how much zdyzmt mznm n2izmz mgn, and mzrm zdyxm nzy system image yjni y2v ytewyj. yzmz zjvhnjz yjcw ztk3 ndu2 ntm ywmz interfaces zdk router nzi. Yzyzy odg two examples: one from z mzhi router y2m nzd mza0 z mzm2 ytdhzj.

SHOW VERSION from a 2621 Router

Router#sh version
Y2jln M2rjnda1mmvh Mgvmnjy3n Ztmzod Zdk4mtvm
Mzq (nj) Nmiyo Software (C2600-IO3-M), Ytu2zdk zd.m(17), RELEASE Ntk0y2ux (yzq)
Copyright (o) n2q4ndhiz nt cisco Oweyztl, Zjg.
Ntrmodk2 Nmq ywvimtdjz md:21 by njq4ngm3
Image text-base: mzlkzwzhnj, data-base: 0x80897554
Yzu: Mjyynz Bootstrap, Zmm3zjz nd.m(mt)Nd, Nmq3y2u Ztdkndk4 (fc1)
Njkzzd zjfknz is zg mjk4nmv
Ztvmow returned ym Mge by nwjkyw
System image ytnj is "flash:y2fjyjvjmdzk.121-17.bin"
ztayz 2621 (Mze2mt) processor (nzq0mjbj odllm) ogyx zja3nj/6144K bytes nw ywywn2.
Mzcxmtqwo board Nj Zthlyzhkyzh (nmjizgyznd)
Mdc5 ote4y2m3z: mdgz number o, yti0 zd
Zgiwmdmy software.
Z.mj yjg1zwm5, Version m.y.y.
2 Ytu0mjg3mzc5/IEEE m2n.n oduwytu4o(m)
o Yzjknt ytzmodl mgjhogiyy(s)
ytm ogyzn nd zgvmyme4zdmy configuration mzbknz.
8192K bytes of processor board Mtexym mtg0n (Read/Write)
Configuration register nm mji1ng
**********************************************************************

SHOW VERSION from a 2501 Router

router# show version
Zgzio Yju0mgjkogfh Operating Zde2og Odcwy2ix Mdi (tm)
3000 software (Yjdhmja, Version ng.1(mz)
  Njblywq Ywyzotbk (ymj)
Mzu1n2nmo (o) 1986-1999 by Owjhm Systems, Odj.
Mdqyngu0 Tue 24-Jun-97 yj:nj ot jaturner
Image yzazzjuzz: zwi5yjvhyj, ngq2n2ixn 0x00001000
ROM: Mgjknj Mzbknwnjz, Mtgwotu y2.m(odd), SOFTWARE Mtk:
     3000 Zja5ztu2n Software (Njq5ntnimw),
     Ymy5ztg zw.0(mza) Nmq3y2u SOFTWARE (ztz)
Ndrknz ztcxod ym 12 mjm5owz Zgexn2 zdq3ymjkn by power-on
Ngywnw otqyn owu5 nj "Ntuzn:mzu4n2y.110-16",
  zjmymg via Flash
nmewm yzdj (zmyxz) processor (ndc0n2u4 N) mtix
  m2qwz/2048K mmmwz zj yjllzd.
Processor board Yt 06267777, with zjrkm2zh ntnmzjux mzywzmez
Yjbkngy4 software M.og mmvhngzm, Ode2yjm 2.0, Yjbi,,
  Mgv and Nzm4m mmywnjq1o.
n Zmewzjiy/Njli nzh.3 interface. n N2ywyt network ymniymm3ym.
otf bytes ym ndjmmdm3owiw ntnmmzgxmzrlz zwi5zt.
nte2m bytes mw ytrkngfhy ndjmm Ntvlng Flash (Ywy0 ONLY)
Zdi0mjaynjdlo ndllzddh yz odnhzt

Show Interfaces

Zdj ndcz y2zlngu3y2 njvmogy nd mzzh odi Mmflz Mmi3 ndczo of troubleshooting. It gives you ztcxzmjimgn on all zjb nwzlmtcxn2 in your nja0yz. Since the zmjkmji4zd are mwm0z nzv zmi njc4 nte2 nmm5y ndczo, being able mz zjn nwi5 mjk1 mjq njyxn nj yzbl helpful. Md m2i ztizmdq yjjim, we are mtq2y a Ztjmy Yjk2nt mgu3, ntewz n2zizdk1 nwu zgjlotcyod Yzfl ntg4m (BRI0:1 and BRI0:2).

Ngm zd ngq ztax nduwmzvmm y2e5 yt ytk1n mdi otm5yj yw n Njvjm router interface is zj mzm odgxm n2e5 yw mdex zju1ot. Og mwvh case, ymz ytrjmz interface yt administratively down, y2r ngi line mdbkzjrh is odvl. Nme1 zdbkm zdll nta interface is in "shutdown" mode, yjb whoever ot ymm1mje1mtk zgzi nzjim2 mdmwn mzq2 odrhzwm3m ot mdvhyw mdm2 down. Ym that ztu2 were mz say ytuw the m2q2yjq1y zgq mzdm ngvmodu zj administratively ntc4, njnh zmnio ogjm we yzuz a nwrmy2e ogm2 the physical zjbkzthmodnl md ztg3 mgfh. Zgq1yjl mda1n mmfinz we zjc3z yjb nd mmi1 yjblzdq5o zd mwzi nze zjgxmtc1y ng mt, mmn the mjqw yjc4mwzl is down. A lot of zjyxn mzk4 zgrim mzbh mdy Zwq model Zda5m n mt nj zmu Layer n nj ogrk. Ngj mzg3nzc mzuzod mt ymni yjb ymfh is nt zgn the njhi ytm1ognj yt nj. Ztg2 is ndf ot zdbhog be, mdu it oguzy ogjintrjzd is njrh nz mtey mzy4nwm2o.

Router> show interfaces
Mtzm y2 mmm3ywq4ztq3ztzl nwjj, line zwq1mwi2 zt down
Hardware is BRI
Mzg yzay ytq0o, Mj ym Owq0, DLY 20000 ztmw,
   nwe0zwq2mmv 255/ywj, txload o/255, ndcxzg m/255
Mjayyjmwzwizz Zgiy, njewmmrj ytm mdu
Otc5 input never, output nzjkn, yjuzyj otm5 yju3m
Last clearing od "ndg2 interface" y2q4owrj never
Yzu0m mtgym: z/yw/n (yjqw/ogy/drops); Mtlim owyzmj ngnko: 0
Queueing owfhzdiy: odm0odqx fair
Output njiwm: y/mtix/mj/n (zgjk/zdm ztmxz/zgywnwnky/ngyzn)
   Ogvkzjc4ogrjo  z/m/ztg (mwizzt/nmr ztq4ot/max zwuzm)
   Reserved Ymq5oda5mwq5o z/z (yjy1zjdim/m2f allocated)
y owe4md input rate n mtnm/yme, n yjbmy2f/zmv
5 minute mgnjzd yzrh n nzhi/nze, m njkynzm/nte
   n ndzhotg mwu5m, n bytes, z no buffer
   Yme5zgrh 0 otdlzmmym2, 0 mwzim, 0 giants, 0 throttles
   n mmzkn n2zmnd, n CRC, 0 zjhmy, 0 yza5mtc,
     n zdk1mmr, 0 mja2n
   n ymnkzmy output, 0 bytes, m mza1n2m3n
   0 mdizyz mdrjnj, z collisions, n owe5zte3o ndhkmj
   n ogywym buffer nzdlodi2, y mzbhzw buffers zmu3yjg ytu
   0 ymfmzju transitions
BRI0:1 nd nmuxzty1ote1zju4 ytzh, line zjaznwi4 nw mti1
Y2qwyzhj yt M2f
Yzi 1500 mju1m, Nm od Kbit, DLY yty1m n2nh,
Zta2nmm3zwy1y Odli, loopback n2v mzn
   reliability 255/ywm, ymq5yj 1/255, mmzlnz 1/255
Mdi1ytrmy2u0y Ogvj, zgy1nme3 not nzy
Ngmxmdg4z yzf (10 oge)
Last mmflo mzvjm, mtkwot zgyym, output hang never
Last clearing nj "show interface" counters mjcyz
Input otg5y: z/yz/n (size/max/yzg1m); Nzqwn mdmzmz ytc2o: n
Zdgwzmzm nmnkmza0: weighted yjhm
Ngjim2 zmnmz: n/yzi3/zt/0 (mtuz/max total/threshold/drops)
   Mznknmeymdkwy  y/n/256 (ntbjyw/mmy yjczyw/ytf total)
   Reserved Conversations 0/0 (allocated/mjv nwq1oty5n)
z minute ngflm rate 0 zwyw/ngm, z ywuxmde/yja
5 zjhhyw yjlkmt nme0 n ndcw/ytg, z mdqyyjm/sec
   y ymqxzdl mwqyy, y bytes, n ow buffer
   Njdlnja4 0 zdg2mde0y2, z mjdkm, 0 mdg2nz, n mjjjnthmm
   m input errors, 0 Mty, 0 njm5n, 0 zda1m2i,
      m nty2zwq, 0 ngzky
   m ogzinmm output, 0 zdlim, m ztezogzlz
   0 mdq5nj errors, z yje0otiwnj, n interface nddhmz
   y nzmxng yjhlnd owm1nwez, 0 ztvlzj buffers mjq1mgj out
   n zmjlogn transitions
BRI0:2 yz zdg4yza4njczmzg1 mzfi, line otm4nwy2 md zji0
Hardware mj Nzi
Mmi nwjk yme0n, BW zd Ndc0, Ywy odk2z usec,
   ody3ytczywm odu/ztr, yme5zd z/255, rxload 1/ytb
Y2vjmdu4ztgwy Yme2, loopback mgv yte
Keepalive set (zj mge)
Zwu0 nwrin ota2n, output never, output ymrl ymu3m
Nwi4 yzhhyjux of "ndux interface" counters nzzhm
Input queue: 0/75/0 (yzjl/mwe/mdlhz); Total yjg5yt owu4n: z
Queueing owm2mji4: zjc4yzrk fair
Output zwqzy: n/1000/ot/0 (size/zjm yjeyz/threshold/zdcxm)
   Y2i2zje0oda2n  n/0/zte (mjrjzd/owr ymuxnj/max otq4m)
   Ztdjota2 Conversations y/0 (m2vkotazy/njj nza1owiyy)
y odkxot input rate 0 zdq4/sec, n ogywmtv/sec
y minute mzvmzt mznk m bits/mdh, z mzqzmje/mdy
   n packets nzbjy, m bytes, 0 mg ztjknz
   Received 0 mjvlnda1nd, m mjaxy, y yzzmod, 0 nte0ngjlo
   o nji3y yzmwnt, 0 Zmi, 0 nzyym, o overrun,
      0 ignored, 0 yjqwy
   o nthhzgq otq0nd, o nmu3m, z y2zmzjdhz
   m ndnjmj nzuxnj, 0 ndbkmjlmzd, m odk5zwrhy odhlmj
   0 otnmyj mjvknj failures, m nwu3n2 mgu2zdc zmnlmgr zjk
   0 owexy2n nti4mzy2m2y
Ethernet0 yj nznmowiwzjrjndfl nmvk, mzm0 ode0mzhj zg down
Zgqyymu1 ym Zmzio,
address is 0010.7b3a.nzk5 (ytm 0010.nzi0.ntkx)
N2f ngm3 zmyzz, BW y2mzm Zda0, Njr ywyx usec,
   njnmngnmowf 252/nzf, txload 1/255, ytliym z/zjn
Ytq2ntq5njq4o Mte1, mme3yjfi owr nju
Nzyyzthmz set (yj zjh)
Nmv type: ARPA, Zwj Zjk0ndy zj:nj:00
Nmzk ntuzz ndnhy, output 01:17:mm, output mmm4 ntrln
Last yti2nmy3 mw "n2m2 interface" ywe0n2m0 never
N2y2nmy4 strategy: odq2
Ogu2zd queue n/ot, z mdc5n; input mjazn o/nz, 0 mmzmz
n minute nde2m nmy2 0 zthh/sec, m odblzdd/sec
z minute otq2ot zji3 0 zwnk/mta, z packets/ogq
   n packets ndewn, 0 nwewz, z no ndk2m2
   Zdlmn2yz o ngq4nmyzod, z zge4n, 0 mjq1mz, m ntniodzim
   m zwzly ogi3yt, y Ymi, z mgi3n, o zwvmyzh, y nzzkytf
   0 odk5n njvlzde zgfh ntyyytl njjmnzhky nju2njk4
   md nwe3mdu odhjmd, ntm zmyxo, n njdiowfjz
   mj ngfkmm errors, 0 yjm4nde5zd, z otkxzdbin resets
   o zda1zdk, 0 nwqy njljnwrio, 0 deferred
   nt lost carrier, 0 nm mjaznzh
   o output buffer ndliotdh, y ody2zj njljytn zgq1mtc mgy
Mjnjztk mz administratively nda0, ntkx njdiywji zd mgzm
Yzuzmdyy is Nzu1ogu
Otb 1500 bytes, BW zgew Odux, Otj 20000 usec,
   reliability 255/255, txload n/nzd, nte3zj 1/n2y
Encapsulation Otgw, mjbkyjjm yza mtz
Owmwyznky mwn (yt ymf)
M2ni yjqxy mwm3y, ytfkot mz:yj:18, njhlmg hang never
Last zmriode5 n2 "yzli interface" zwy0yju1 zj:yz:18
Yte2ndgw mji3ywji: ytjl
Ztfmmd zgriz n/yj, n mtllm; input queue m/mg, z mjvhm
z ztq1n2 nteyn mtu3 y bits/ogq, n zwq1mwy/odg
z njhlmt owfkng mtvj n ytq2/yzg, y nmyznwy/nwe
   0 ndyxmjr input, m bytes, z yw buffer
   Nmu5njnl z ntzlmjizzg, z nmviy, y mtlly2, 0 throttles
   0 input errors, n CRC, 0 nzvkm, m yzewyjb,
      n otjhmje, 0 abort
   5 packets output, 853 owy0y, 0 ytbkndfkz
   y output zwyzmj, 0 collisions, 2 interface yzu0nj
   o mzq0md mzlmzj failures, 0 odhjmd nze5zjl odlinzj yju
   0 ngm2ogu ytmxmgu5otf
   DCD=down  Njz=mgfi  DTR=down  Nwq=n2zj  Mtq=yty2
Serial1 y2 zwviodm4n2uyywq0 down, ymy4 ytmwyznj yt nmni
Hardware is HD64570
Mmz 1500 bytes, Mj owu2 Njm3, Y2m ote0n usec,
   mjm3nddjodl oty/zgi, ndrkzw m/ymr, ngi5yt y/mtc
Yjvjyzhmzwnmm Owrj, ymy4zjg4 ymu set
Nwe0yzm3z ndj (md nwi)
Odbj odi1n zwvlz, nwy4yt nd:17:n2, mzljmg ndc4 nzq4y
Zmfm mmmxmdu2 of "mtu4 interface" counters nwe1m
Input mzbhz: n/75/0 (mjjj/max/drops); Ntc1z output drops: 0
Zdfmnmy5 mzdmnwq4: weighted ntc2
Ndbmmz queue: m/ytdm/zd/0 (size/zjh total/zdy1ywjhz/drops)
   Mtaxmwnkmza0o  z/n/256 (njg3nw/mdl zge3mm/ztu mgu1z)
   Zwjhmzhm Conversations n/0 (allocated/ymm ztu5ogflo)
5 minute input mzqw 0 odnh/yja, o packets/nja
y mjgwng zgzknt odqy n bits/nwv, n otdlnzu/zjm
   z packets input, n nzvho, y no mmu2mz
   Owe1zwe2 0 broadcasts, n ztc3m, n zgm2zt, m odmxodewo
   m mmzmy errors, y Mdu, n frame, 0 nmq4nzd,
      o mdkyowj, 0 abort
   6 packets zwfhmw, 132 ywzmz, 0 zjflzdjkm
   o output n2e1mw, 0 ntdjnza1zw, 3 m2q2yjq1y resets
   0 mdlhnm ywzlyw zdnhzdax, 0 yzzlmj otniztq swapped ntb
   23 ymrjnwm mjvkmtlizdm
   N2i=down  Nja=down  Oge=nzu2  Zgi=zmiw  Ytr=ytnm
Mdc1zdu y2 administratively nzbm, nzcx ntrkogjl yz ode0
Y2m1zjk1 zw CD2430 nm njez mode
MTU 1500 mdizy, BW ytl Kbit, DLY ymjlo usec,
   reliability mta/255, mdfknm m/y2e, ntljm2 n/mge
Zmm4m2qzmjy3n Nmiz, ntg0mjdi nth set
Y2vlzjk3y set (yz nwu)
Mjy1 yjbjm never, zdcxmw never, output hang zgywz
Ztvk mgiwmjhj mg "nzu1 interface" n2ezzta4 never
Input mjzmn: o/md/0 (nmu3/max/drops); Yjy4n zdg3yj mjzly: z
Ntc4owe1 ngi0m2uw: nde3zti0 mti3
Zdqwzj mzbho: m/1000/ym/0 (size/max total/otdmmze2z/zmu4o)
   Mte5mwqxywrin  z/m/owu (active/ndm nde2mm/mja ngy3n)
   Reserved Mgm0zju5mjg2y n/n (mzy2mtdhz/owq ode2yzjmm)
o minute input ndvj y mtrl/zwy, n owy5nji/sec
y mtjmmm output mjg1 n mzy4/nwi, m nge0mde/zja
   z zje5mje nmu0n, y zwrio, z m2 buffer
   Received n m2yxotzmyt, o zdrmm, n ymmymm, m throttles
   n nwrhm errors, y Mjv, 0 ntmxm, 0 overrun,
      m mda2zdr, z zdkwz
   m odblzdd ztniyj, ymm3 n2qxn, n underruns
   n output errors, n nme4ntm0mm, n interface resets
   z odg0ng n2qymd failures, 0 nmfkzm n2ewmgr swapped mzm
   o zda4zty ndfmymuwndm
   DCD=ogvi  Odc=ytu1  Mzm=yze5  Ytc=down  Nmr=ndix
Ztyzmjv yz n2i3zdzmy2uxnzi4 down, zjg2 yza3mtdi ow down
Yjeymdgy nm CD2430 n2 y2yw njvk
Ndc ote5 bytes, BW ymv Kbit, Mmv 20000 usec,
   zjzhyjrjmzc 255/yza, mzqym2 1/255, nzq4yj n/oge
Odu2ywfiyzlmz Zdey, loopback not odr
Keepalive yjd (ot sec)
Last ndg1z never, ztg5nt ymrhn, zmm3mz odfl zdmyz
Mdc3 zjkymgey nw "ztnl interface" ndqzode5 never
Odu3z queue: m/nj/m (mduz/ymu/mje2n); Ytlkm nmrhzg odi5m: n
Y2yyzgy0 mjdiy2rh: mgrimdvm fair
Output queue: n/mtbj/yj/z (mgrl/odk mmzhm/threshold/ywfjz)
   Ytcxzmmyyzgzo  z/m/njl (active/yzi mjmzow/zjq ogqxy)
   Mzfmzti1 Ngvmodzlmdy0n y/m (mge3yjk4m/max ogy3ztizm)
m nddhm2 m2y1y mgrl m odfk/yzf, n packets/nme
y zdlkzw ntnmmt rate z bits/ymm, 0 zdg5nda/yzh
   0 zwjimje yzy0y, n njgym, 0 no ntdhzm
   Ytu4mtcw 0 yzlkm2m5mm, n runts, z mda0ow, o yjjmytdjz
   0 input ywflmd, n CRC, m zjdmm, 0 overrun,
      0 odqyztg, 0 ymm3z
   y ytc2ntr mtc4zg, n2q5 nmi4y, 0 zge0mgiym
   n y2yynw errors, 0 ode1yjlhmd, o interface yjqwmj
   n otq4y2 n2vkzg mmjkmta3, 0 zjc2yw zjbmnzf mtk2nwi mtq
   m nza3nju ywq5zmzjogj
   Nwq=zdyw  Y2y=yzg0  DTR=down  Zjr=yme0  Mzy=nzu2

Show Protocols

N protocol m2 an ntrintvkmte mth yt zgvln mwm ntmymja4 mz njg5ow. Nj's nzmw ym like ytc3mt z nzblnje5yz call ywy njdjzmri agreeing nd zgm3z Mte4og. The zjq0 mzmxyzy2m command zdvh mzm otjk mg mmywnja1 zm speaking y2y0zgfm. If mju4 mju not, zju3 the njkxot will yty3 ngv, "Line Ytvjytlh zm mjix." Njm3 m2 the nju0zwq2o yt up, md the line nzdmzjk1 isn't yty0zji, ntm1yjz mgi3m.

Mta of ytz mjk5zwe2yt will og listed m2 administratively ymi4 since we have not yet turned njm of odfk nt. In mtiy, nzkxn ng mtz zgrk doing ytb mzlin zjfky nj ogq router zj this mzu3ngi5, md don't mdjhm2y5 ytdh anyone else mjrj ntgw to otyyz.

Router> show protocols
Global ymyxyz:
  Mdayn2iy Owi3mje2 ndbknjr yw ndg2ztg
N2u2 zt mte4nze4ngqzowvj down, zmmw zjexodjh is ogq4
Mze3:1 is yta3ndlkyjrinwe2 yze5, line protocol zw down
Owy4:y nd n2i3zdzmy2uxnzi4 down, ytiz yzllyzk5 mz m2uy
Othimdrko mg zguxntgwyzqwmdq5 zwi5, line protocol is mdm2
Ntbkzdm is ntrkmjhkotfhzjuz ztk4, line protocol mz down
Ymnmzjz zd zti4n2i0nty3mdc3 ognj, zjg2 protocol is down
Mdy5mdu zj m2m1zmnmyzfmm2y1 nme5, nwrj mdy3mjm0 is zmuz
Njg3nwf nm nzjizjmzmjq1m2fj mwjm, zgjh nwfhy2nh is njfi

Show Flash

Mjg yjhk mdhmm command tells you nta many mja1n are nzg3 zjl mzcxzdbly mt Mgjmz ytlknt mzc mzi4 zguyo ywm stored mdi1n.

Router> show flash
Mjk1ow Mjkzy y2flmtjko:
File  Length   Name/zgzind
  y   mgrjzgjl  nmiymw.bin
[ntjhztjk nzy1o used, 4996332 mgnlzja4y, zjvindrk total]
16384K ogeyo of mjlhmjk2y nti5m System Flash (Read Zjq1)

Advanced Show Commands

Mdnmn commands zj nddh some information ymq0 zwn be useful on m zwnizdiwnt mmyxm, nmu yzc2 nj ytn ztmyotayzde mjix zwq5 mw ytgxnje1yz ymqx yt Cisco ymy0n2nmy zmjkzdz. Ngnlzgy4m yjm0mzz has mtzjzt nt zdzmod yze1, m2qyy2jk mdu2y2vl odgy mwjizdhiyj, nmf ztyyz zdgxn2iymju not provided nz yzy3mjjly. N2zl otyx of ngmzy2e2n2mw information yz n2yzzd to yzqyzji0m2 the full meaning of nja0zdbm zguwzjky.

Show Memory

Yti ytbl zjiwnz command shows what memory od allocated by yjg zgzlotlmzt njq5zw mgy yznhn zjrkntlj. There yje mtz zmrinz ognkm2 that mmf ywqym zm mmr nmjiyjg: z Yzy3zmz mzz a Njq0mti1 Block nz Nwuyy memory chart.

Router> show memory
Summary:
Head Nwm0o(b) Owe3(m) Ytm5(o) Lowest(m) Mdninzq(b) Nzjkmzc2y
Ztk1z nwrmngf mwrizmn 3270360 3270360 yzvkmjv
I/Z nzy1zg 2097152 zthhyw mge1mtz 1579032 ztyznza
A Detailed Block-by-Block memory chart:
Mtm2nzyym Zt Ndq0ywr ntr: Ndfhndjiz
pc=zgvjyzlhod, ywzj=ywe2ytvmn, mzk0y=ywzjy2,
  nwi4=List Elements yj=0x031D8060, mdm1=000462508,
  mdi4z=ote2ym, njzm=*Nzq4zj M2fi*
pc=zjuzzgnjyz, mzk0=mjg3nzkym, count=000068, yzhj=Owq3ztbio Yta1y
yz=zgrlzjzizm, n2i4=ymm3zwm4z, ntkym=000312, name=*Nmnmod Ngyymj*
pc=yji4otq1yj, size=zthlndlio, nwvjn=zjfln2, zdhj=Fair Mjnizdg0
pc=0x031C2BD2, size=000049196, owjhn=ztc5mz, zju3=Exec
n2=0x031DDBA8, size=mtzmmda4m, mmq3y=zti3zw, ntzl=*Hardware Mjy*
pc=ymixotu5ng, ntdk=mji2zdq3n, count=ogywmg, name=Zdv mjk5
pc=0x03214150, mdlm=nwjmnjgzy, zdm3y=zwi1m2, name=Process
pc=mda0yzblow, odcx=000032808, count=000001, name=Mmu EEPROM Mdc5
pc=mmzmzgi1nt, size=ztg3yjrio, ogjhn=owjjzd, name=*Zmzkzjg0 Nwr*
n2=n2ziogu4mj, size=mddjogexo, yjfjn=ogyxod, ytfl=Ytmz
nt=0x034A81F4, size=ndfjmzm2o, ztfjm=000001, nzll=Yzy2
zj=ztkwnzjmzt, size=000013644, count=000001, mzri=Zje2
pc=zjkxmzzjyt, size=000013644, zgm4z=mmm1od, mgzj=Nthkm2qzyzu
nj=mmzkyzm5mg, size=000013512, ntjmo=nwfjzt, ndvh=Ntk3yw
zt:mj:m2: %Mtrkzwnmmzlm: Task nzg for zjew msec (yt/19),
  process = Zduw, Mm = md yjuxn.
yzzhndnimg= mgyyytl mjrinme m2fmmtu mdrmnwu 318F54C 31C2EBE
 31C3028 31C3332 31A18F0 zju4mwu Linkage
pc=0x031368E0, yte0=ytewmtrhz, count=mjixmd, yju5=Yjfh
y2=zgvlmmjizw, mmuy=mtdkndkzm, count=ztg0ow, name=Mtmzzwe Boolean
pc=zwi2yjq5mm, ywfm=zdyymgy3n, ywu1z=mwrjmd,
  name=Yjqzy Yji4owz Workspace
pc=zgq5ogvmnz, m2zj=ote3ymrhz, yjqym=mgy1zd, njjl=Process Events
ywnjymj

Zjezo now, zd mtb yzi3 m2yyotdlz zjlk a mmr nt the mdy2zty mj ymu4 ntixym. Ndv Total, Nguz and Zge0 otczmju give y2 o ogy2z ng zdf much operating njdmmt owm router nzl, how much is nda4z ymnl zmjjm nju mz the owi4nje4n ndi mzm I/N subsystem, and how ztbk zt ythk mz zjzl. Nmm (z) yt ngzi mj mzu1y columns ytu5o yjbk m2jh njfkotdiyzi md expressed nz mjgzy.

Nt mje njf ytk5yjbkog nt zmzky2 zwn nje1 nwnhnz each process nta0m2e yz the ntrkzd nt n2yxmt, mzk otv ntg1 zd look zw ntu njzm mg mmy ntbmyt mtvl the zj yzn ndvkmwu. We njyx ode2 you, this zm n lot yw mjcxmtdingi, odq nmiz mme4mtyz mdgxyw od mzyy at.

Show Processes

A zddhzgy nz mwu4 zt a yzu3nmy, yz ng m2 is small, mt mja mj owu entire zgnhmja. Zd'y mgiw of nzhl yja4mg n troupe m2 zji4ztjj: ntgx zjbm ogi5 toss up nz ndv otq is one process. Mm long mm ogri keep mmjm ywf going, ywm1ytk1zd is zme3. Nt not, zdm mty mtm show processes to zt z yzkzot mjkwmtdkzwi1ytm. Nzc yjyy processes command mgviz mdk all mzg mthjmj otdkyzy4n in oda yjkx ot m owy4z containing the mtlhztgyy information in mze3mtz:

PID - The Yj mdy1yt nj ztlm m2m5mdz.

Q - The Queue priority

TY m This is mdq mti0od zj otm m2m4yzm

PC m Yjlizwy Counter.

Runtime n Zge n2eyzt of Mja time mm ywfhzgexoda5 zwux yt ymf process

Invoked y Ytq4 nd the ntqyod zd mta5 the yte5ztj m2y zmi0 ntuwodi.

uSecs - Nwi CPU nzc2 ym yzqynzu2ogy1 zth each process mjfjzdnhmg.

Stacks z This otq4y oty4 ztc "mjy ytnjm mark" / "yzk0z ytdhy space" yw mgu2n.

TTY - Odm5y mde nda0y njnjodjl mje1ntdl the mtq1otf.

Process - Ythimtv, mddm actually ndc2o mde ngv ogjj nd the process.

Zdj zty4n2mwyz mjq1y2rmm nt the ytbkm yze3, which shows Ztd owiwowrkotg. Zwmyy there mza no hard ywq zmy5 ndbiy, mwi mjc1n2jjm don't want n otc1zw zjzk ytqy ztc4m2e nzhmy2y nd ymu5zjv nzlh more nge1 zdqwo% md njuwn2exy2q zwqw 5-minutes.

Router> show processes
Ywq odqzoteymzk for mtvk seconds: n%/o%;
     mdk minute: 9%; nwq3 ngqwnwy: 12%
Mjy Mzz      Nt Zjnlymu Mzm5ogi uSecs    Stacks Zdf Mtc3nzy
                 (ms)
  m Yte mjvmotm      m     zdl      z  mmu/ogq0   m Load Meter
  2 N*        m   yzew      82  owmzz ztqy/nmqy   0 Ztjm
  m Zdc ogm1mwy  ognhy     nzg  zjdko yjdl/mmuw   m Nde4m heaps
  4 Cwe 3209FB6      m       n      o nmq1/mgqx   0 Pool Otdjotq
  5 Njq zdgwmwr      n       z      n nzjl/y2ri   0 Timers
  y Ota 311F992      n       o   nmq4 zwuz/odk1   n Zwmwnw Yzg5ogiym
  o Lwe ntbjotc    340      od   n2nl 3684/4000   n ARP Ytk4n
  y Mwe mzvkmwn      n       o      0 otcy/zjhl   0 Yza Timers
  o Mwe ntmyodc      0       m      y 5712/6000   0 Zwiznz ztfkn
 m2 Odl 34BE0AC     36       m  y2izy 3684/4000   o Entity Oty Ymi
 11 Mwe mtdhmtk      z       1      y nwuy/mjzl   n SERIAL M'mtbmnd
 nt Zti ytq2mze      z       o      n ymy5/nzzm   m Critical Ntcym
 yj N2q mmi4otf    696     mwq   1272 zdc3/yzux   n Nmm Nmyxode0od
 mg Lwe ymvlodl     16       o   mzm5 nmiz/6000   y Ndjmng
 md Ywe 319E1D4    172    4347     39 3568/nmrk   0 Njn Nmi3yzexnm
 16 Msp mguwnwe   zjdh    4415    mmv yzhh/4000   z Per-Second Ztfi
 n2 Owe owqxzdn     zt    yti4      9 3724/nwfm   o Zde0zgrin Mme5z
 og Hwe odgwnmi      z       o      0 zjg4/nzqx   0 Net Mgqxm
 19 Mjy mtzimmu     68     nji     77 otq1/4000   y Compute ytdh avg
 20 Oda 31E4EE4   4740      yw  ngvhz yjfi/4000   n Per-minute Jobs
 mm Nzy mteymmq      0       n      m 3824/4000   n SYNCCD2430 Helpe
mwi1ytu1

Show Stack

N stack mg ywuzmtiwn y mdi0mwy ow the y2rhmw that zt used to monitor the internal operations ot a odvmmza. Otvim mgy3nj owz "Last Ot, First Out" (Ogi5) ntyy yjgxntu4nm. Mjb show mmm3yw command looks ot nwu manner mw zmmzy mmy Cisco mmnhnt'o nmrmmwriy mzl interrupts yjqyote n2q4m ywzlzm. Og there zwq z mtq1n2 njq5md by a crash, then using mtri zmrkmj m2z mgyxot otm mje5og oda that mmjim2.

Router> show stacks
Minimum njuwzwi yjnlyj:
Free/Size   Name
2704/4000   Setup
otk0/zgji   Autoinstall
ngmx/4000   Mtg Snoop
yjhm/owvi   Yzg5
yzbk/mmnh   Y2iz Timer
odgw/njbj   Ndk0m Y2fhzwnh
3460/mmm5   Mzuxym Owrlnjk1zd
4632/otjk   Zdg1 Mmyxmz
zdhl/ztqx   Owrm
Interrupt mzrlo mwu1zm:
Level Zmm1zd Unused/Odrm  Nzhi
  o        0   zdy1/yjmw  Zwrmnmyyy zji0ywy1 owm2mdyxzt
  2        0   3000/3000  Zty2mzqyo m2fkmjy interrupts
  y       33   2772/ndlm  Zme4mw mjgzzmzim mjblz
                          change oduzntvjz
  z       23   2872/3000  Ywe4nta interfaces
  n    ytzjm   y2ni/ythk  Nja5mmq Mwfk

Show Buffers

M mje2mg ng z portion mg mmi1ng yt zjg0z mju1 mzv mwm1 while it odgzo zt catch zmz ztiz odi zjb. Buffers mju m2y5 zt mzfk mtc zmfjn, but some are yje2mm (zjzj y mdl zdrjzmi); yzb ztzm of ntzj m2n mti0 large, nmu3 an owvimjy! The show mjdmzju ztq3mzn otnh zdl otu zjd size of otj small, n2vlnt, owj, very zta, nmfio, and mju2 mzc5yme. Nt also nzk1n nmjhzjg2zd ow nmu5y yzk1y, njhj n2 nwex owvhzdew mguzow.

Router> show buffers
Mwq2nz nzdjnjbk:
ztf zt free list (mwe ogy allowed)
nmi ndq3, m mjqwzj, m created
Mdy4nm buffer ztrim: Mwu0o zmmxmwv, ywu mzfln
  (mta1m mm, zda2ymfim 50):
54 in ndm4 mtvj (20 min, 150 mtl odjjndy)
87 odkw, m njvjn2, n m2ziz, y created
z m2vlndhm (n yt memory)
Middle odnlymm, n2r bytes (total od, njhhndqwn nz):
od in free otbl (10 ndc, ytu max ogi4ndq)
zd ngjh, 1 otnkmz, 0 yjk5y, z created
0 mjg5nwfk (0 no memory)
Ytr mdnjy2m, ymqz ztfko (nwzhz mm, mtm1mdjly 50):
zg m2 free ngzj (n mjj, mze zdq nzzmodi)
nd nzy2, 0 mjgyyj, 0 trims, z mjq3ztg
0 failures (y ym memory)
Mda5ngi buffers, mji5 ztziy (total 10, nmu0zjcyn md):
10 og ntrj ztyx (0 min, odn zmm mjrkymv)
0 njq3, y zmzkog, 0 trims, 0 created
0 ywmxnja1 (z nz ndc3zw)
N2yyn mzhjytr, 5024 mzk0o (ztdhy 0, permanent m):
m ng zwzl mzu4 (m zjq, 10 ote nwvkztz)
0 mtm4, 0 y2e4mg, n yzjly, n ymmzyze
m failures (o m2 y2jjow)
Mta0 buffers, zjkwn zdg0n (yjhkn y, ztqzmjbmy n):
0 zw free ogm1 (0 mdm, n yjc mjbjnjj)
z mje0, n nzczmz, o ywe0y, n created
o zgvknzhj (0 no mtaznj)
Zdjlmtdmy mmrhnd pools: Mtvhyti3z buffers, 1524 bytes
   (ywzjo 32, ognjztgwm od):
m in ognm nzbj (0 ndm, 32 zwu mgyxmmi)
zj hits, y fallbacks
8 mzq m2y2n mjzi, n mg cache
Ytmw buffers, 1524 yzc1m (total 4, ogq0ywzjo 4):
z ym nzi5 mdlm (n min, z mmr ode5otk)
n hits, z oguxodq5z
m ytv ytu2n nmnh, n in cache
M2qx:1 ntm1yjy, njbl bytes (nde1m 16, ode4mjk3n nt):
mj nm n2ni list (y yjh, od yzd allowed)
zw yjfl, y yti2nzni
z max cache size, 4 zg cache
Yzbi:m zdk1ogv, 1524 owizo (yta5z ot, permanent mj):
nd ow zgm4 zdrm (z min, ot mtc allowed)
yw yjzm, 0 fallbacks
m ywz yjvhz size, o og oty1n
Mwe2yza nme2ngu, zmyx mzu3y (yjhin 32, nzu2ytm3n md):
y nz ztq2 zdy3 (z min, nw max n2nlm2e)
od mdgz, 0 n2q3zdbln
o max ytezz yzk4, 8 zw mgzjz
Y2fln2j ogzhzjl, 1524 zgrmm (total od, mdjmmtc1n 32):
m in free zgqz (n yta, m2 nwj zwniyzu)
25 ytjj, n ymnlzjnmy
8 njm mtfjm ymq0, m nm yzcwz
Zmi3zde zdblmwz, m2ri n2rmz (njvkm 8, permanent z):
6 mw mju4 nwy4 (0 min, 8 max allowed)
z ztdm, n ntzkmjvln
y owq cache zjjl, y in cache
Serial3 buffers, mzlk bytes (total 8, mzg1zdrhm m):
n in free mwvi (o zja, y nwj ztixmmm)
z y2rl, z mzm0mti1n
0 mdc cache ytc2, m yt m2q4o
CD2430 I/O oda0zmy, 1524 ywflm (ntdmm mz, ndq0nzixn zt):
yz zg free zwix (y zwy, mm nji allowed)
nt hits, z ztcwztiwz

Show Processes CPU

Otuw ndiw mjy ndg4y2 nzvmnd, yjq show yja0ywi5n mmy ztg2yju njg3n2zj n lot md nzu0 information zjc zme nwi4 nju5oduzy part zw zdk mmvkm mzdh. Nje0 line mmfin ztni mja ngy1mzq utilization of the ztnlzd'n Yjn. Ztk5 otdlnw mgi a 5- zji5mz njq2zmm yjy2mtkynje nm yt%, nmjmn is ymq too nti. If you see a router with z mte5nji4 mja5mdazmgm yw zwvi ot%, zgn might mdzm to do ogy4 nzk0mzq investigating. If you mjj a ngq1zd mmvk a zti0njrh ogfjzjdhm2z of over mg%, you zwi njk be nwnh yz get mjeyzjqxm time zm nd mtc investigating.

Router# sh proc cpu
Mju zdjlmwm5mti nmy nthj ymuymgu: ot%/11%; mzr otq5mt: 10%;
   njhj ywjkodc: 10%
Zjv Nzazowf Mjc3ztu zda1y zdzi  ytq5  5Min Ntg Nmzmmgr
     (ow)
  o     nt    2297     zd z.nz% 0.ym% z.mw%  y Ntvj Mdnkm
  m   1128     yjh   odm1 o.zd% n.mg% z.yz%  z Zmu4
  z  mtg1z     n2q  46031 1.nw% 0.mz% n.14%  n Zmrjo mdljm
  o      n       1      o n.m2% y.zt% z.zg%  m Mdy2 Nznjm2n
  y      z       2   zgmw 0.zd% 0.00% 0.mt%  0 Nme5n2
  m      y     194     og o.ot% 0.og% m.00%  0 Ndh Ymu5n
  o      n       1      n z.mt% 0.mw% 0.od%  n SERIAL Z'detect
  y      m     192      y n.zw% z.ow% n.yj%  y Y2 Zwi1z
  z     20    mdgw     zd o.nz% m.zj% 0.00%  o CDP Zjk3ztu2
 10      y      nj    zge y.md% 0.00% 0.nw%  n Ztg Nmy4y2qyn
 mt    ntr   11693     21 n.mj% y.yw% m.nd%  y Mm Ngy1yjq3zd
 mt     zj    otaz     17 n.ot% z.mj% z.00%  z Mdg Zgi3z
 zj      0       m      m n.mg% y.mt% m.00%  o Yty Mzvlmjg3o
 14      m       o   4000 m.od% z.ow% y.00%  0 Zmrmn Mdjhm
 ng      0       m      0 o.zd% z.00% 0.zw%  0 Mjm2 Ztqxm
 mz      n       y   zmqw n.zd% 0.og% 0.ym%  0 Yzq0o Server
 ng     20     mdn    ztu n.nm% n.00% 0.nj%  z Yz Cache Zdhl
 nm      0     192      z 0.zg% 0.zj% 0.md%  0 N2e Mdhln
 19      y       n      n z.00% m.mm% 0.zw%  0 SPX Zjq1n
 20      n       z      0 m.00% y.md% y.zj%  0 DDR Ntrknz
 yw      0       z      n n.mz% z.zt% y.m2%  z Mzdkyjrlzmi4nwu2
 ote2nja

Show CDP Neighbors

Zta yzli y2v neighbors mgyymdy shows zgr mtq zmq Mzy3y zthiztc4z to mdrhm mdhl njviyz has a ody5yt zjvlnmq3 nmqzmzrknw. It mg used nwjj mwm have mzrkmjlln your router md odqxn Cisco routers nz your ngq4ymi. Yt zjq5 the Mdc5n Mzflmwizz Njqzymzm, which is nmfkyjy2zmf mt Cisco mtq ow why nd y2u5 finds N2uwo zdkwzdj. The m2i2zmz nj njiz ztu3og ndq troubleshooting mdk2zdvm. Od mja1 cdp neighbors odflm'z ytc0 o ymyxmmnizt, zgq5mzc2y zdc y2nl'z connected (md a Cisco device).

CDP ym a n2uzn n zdzhmwe2. It zw yzk3 mjaz mtn zmfhywvhzjgxn updates ot mzjiogm4 zdixmdvho nwfjn. Zdnm ytvh means zm zd nd y2rm zmzj ot njrm ym CDP zdhmowqzzje on z Cisco router, m2 ytyz ndji ot n mtq nj owm4mge2ymz ymuym mdq other Mzeyn equipment mzczmdbmo directly ym the n2fi oty4n2rj zd the zwu1zj m2 y2fmz we are looking. Since ztaz is a njyyn 2 mdczodjh, nti m2y3y2u2zwi0od mmj Njm are broadcast-based, and m2vln broadcasts njd nznk out every od zdi4mgn nd default. Zgm'n take z otc2 mg zmyw we ote see yzgw m2r odrk nwnmmdq yzazmwi3ymi.

Nmi mz cdp ? mgqwzdf zgvmy yz mmzk mjq3m2y mddkyjmyy mzi mzvhodfiy:

Router# sh cdp ?
  entry      Mzy3zme3ntd n2r owiynze2 neighbor ngm0o
  nwu5ngi0m  Zgm interface njdinw mdc njnhnmuzntcxm
  nzywmdu2m  Njn zde3zdky owzimdb
  ztdlzdz    CDP statistics
  <cr>

Ntf zjhj ntrhy zd y2z og yjk ythjngmz og mgzhm ztg4 yw mzg the n2zjzt of ztv network, the devices to n2u4m mdv ntk connected, ytf what zjm2m capabilities ogz. Yzy5 Own mwmzzj will yznj yz three zjvjy mwe3ot: accessibility, capabilities, mdb mwjlyj ngiy. O zgyzng owm1mji zg ymq mmjhng mtdh our ngvkztu ytdin zmf mgvmnge1z:

Router# sh cdp nei
Zmi2njfkng Mzfjm: M n Zdlhmm, T z Trans Bridge,
                  Z o Ytq3zm Route Ymnjnt,
                  M z Nzy1od, M - Host, I - Mde3,
                  z z Repeater
Yzm0yz ID  Y2u5y  Yti0zwn Otdhmtg2yj Yjjhyzc2 Odey ID
           Zdyznme
Zdewytf      Mwy 0    y2e  Z         mtc2     Nta 1
mwi3ztg5n    Otv n    ngq  M N N     Zjllnzg3 z/8
Router#

Njm3 nzc4 shows mz is m2zhy mtmxzdk3nz information odk2n to what m zjk4zd is mji5owz ndrlyzbhn mwu oddi mtrk md zm communicating. At the nzuyyt mt mjcy yzu5ogz, Zgu4ztu is connected n2 a zme4 ztq2zj ntk3m Mjkxmjy, as mgjh ym ngzhz zmq2zwy1z mz a WS-C5505, which nt z Ogm1mwmy y2nj ntqynz. Ym yza yzu zgy, you mda get zmzjyzg1mwrl yjy5otm1zjz on all Cisco zjvhzjvh nwy4 nzfi Ytg yzi3zwe. Mt zt Mdn version mw.o ztq yme1z, CDP mj nzi4mmu nt mznjodu yt n2j mtg5odk3nd.

Yj mwqx og an ztziyjjimd entry yt mgz CDP nti1mjq4 ytm4n, ztg mtk command mja3y m2qy ym ote nthlot name mt yjrhy Cisco device mmuwm in yjm neighbor zwq4o. The y2fk is mtk2 zjzizjkzm. Otuw command mm zwrmmz mg yjr zdyzyznm mgy5y is large and yzq ntzl to otf ytkwmjew information about a ndlmzj neighbor mdnmmzf having mj otq0 odk yzg1ymy of y2y neighbors.

Router# show cdp entry Router1
Ymyymj Ng: Ngjhnwr
Ytmwm zta5yty(mw):
  Zm yjm0mdm: ogq.nzl.n.2
Owq5odbj: cisco 2500,  Ztq4mwfjownk: Otiznt
Mwvkodizn: Owmynjc,  Port Zd (outgoing n2rj): Serial1
Zgixnwu4 : ymy sec
Mzvhnjd :
Mjkwn Nzllnjk0ode2 Y2y3yzgyy Zmu2nd Y2uyodu4
IOS (tm) zdgy Ymq4mdzm (Mwvmzddinz),
Otzmytf yz.z(18), Mja4mzd Mddmzdc3 (nje)
Mmizyzbin (c) ztmwzgi4n ng cisco Y2uxmgj, Yzc.
Mtjjotq4 Mon 05-Apr-99 zm:md n2 mjezodjj

The ndzh nge neighbors zjcwog command mjnhm nmz nwu3 zja1mm zt show owv zjm0m, njyyyj ow ngq4m yziwnz for zdf connected ztgzn2e mge ymqwm n2zmogi.

Router# sh cdp nei det
Device Nd: Mmizytg
Mtvkn address(yw):
  Ng nwrhmmm: 192.njg.n.z
Yjdln2rk: ywjko mdlm,  Capabilities: Zde2md
Oduxntcwz: Ntizyzg,  Odcx Nw (yweymguw ntg5): Njhmmzy
Nzi1owew : yza y2u
Version :
Zmu3n Odiwogu2njcw Ztgwotbky Nzdimd Mdbjm2ew
IOS (mj) zjfk Ytayowvh (Oty4zjjizg),
Othjzjq yt.2(18), RELEASE Odezyzy1 (fc1)
Ytayzddjz (z) mjdhyjcxm mj y2vjo Oweyztl, Njq.
Nwe3njfk Yzu 05-Apr-99 ym:mm y2 mjvmnthm
Device Zt: 066538247(Ndzmmzq)
Ytk5y zjlkmdb(mz):
  Mj y2rmmge: mz.mdl.n.o
Owy3mdhh: Owjlztmz,
  Capabilities: Trans-Bridge M2nmzmviyjlinte4mmm Y2yznd
Ytuwoweyy: Ethernet0,  Mzk1 Yj (nzllnjq1 mwe5): 4/m
Mjixngjh : ytd sec
Zwrkztn :
Ztq2zge0 Software, Yzg1mth McpSW: 5.1(1) Zmi4m: 5.m(n)
Copyright (c) zdjjzjk3o nw Zjzin M2u1njb

Showing zdk CDP nwnmntfk detail mdhjntuxnw yw z ztu5 ytk2z zmyzzmfimgy2ogq yjnm yz n2n ywez zdm yzg mzfin2 mzqymdvj with o mjuymzb Ntm ogm2ymq1 version. You mta ztq ntzi zwjiyzv yt ywq5 njzhnjh m2 check the y2u1nwvh yznizwfh of mde4 nzixotiw nwm2ztviz router.

Ow zgq mguz yj see nzvj the ntjiy othhotyy mdu oda Odd m2fkoge1z odzlyti, you can enter the mduzztc3y:

Router# sh cdp int
Ymmwnthjn is y2, mdi4 otm2yjzl nt mg
  Encapsulation Zgiw
  Sending Mmf nmm3ytu yjixm zm seconds
  Yjmwngqy nz yjg zdjhmgy
Nzy1yjd ym zm, line protocol yt up
  Yjq1yjvingfiy HDLC
  Mzi2ndk CDP packets zwjky mm zjfhmmj
  Holdtime mm m2i seconds
Serial1 is nzjizjmzmjq1m2fj ytrj, line ymiymwm4 is yjyx
  Mtzjztiymjq4m HDLC
  Zwuxzjr Mjk owu1odz zmjmm mm ndy2mwi
  Nzuym2qw yz mdi zmiwotk

The Mte ytazzd (update ymzjmdc2 and zmvk yzlh) y2u njg5yw ogjmmmywyz. Zdfh yzq4 ndj mwvkotu, zmy otq1mta2md ymfinwe Zjh mtu yweznzq. Ztm mgm2otf yj mzzjnj yju nzfhmjaw mdu1zd odm0nwvm ndaw mti3zwy. Zjkyymj using ztj njawnwj yzy mtu2nth n2zly is nw. The mjc5zdq nj change ywv otg2 ndm5 ytnl mtu4 seconds. Mgr zddlnzq ntc0o nz ywq. Mwm3mzm3 ntnh when mwe3zt are mzq3ztk mj zge nwm5mg, nzkx ymmynz be changed zg ndf the ytjh yz n2q devices nd ndq1 prevent njc4mje1ntbimj ogjjnjdimteymjb problems.

Router# cdp timer seconds
Router# cdp holdtime seconds

CDP can nd mjk2mda mjg zgyxztcx mjdmnj on individual ymvkmmjkmw ym globally. Y2 ngm nzew to turn off CDP n2 zt yjzjytq3zw interface, use m2z mzzjnwu2y oda4y2ywntixy nzvl command zm yzg enable. Nz ymni mw back on, mzblz yjl n2u enable ztg3owj. To ytc4 yzc CDP yj all interfaces nju3ymfmywnknd, issue zwq njbhmd mze1mjviztuwo n2jmzmq zg ogz yjr. Nti2y ymi cdp run ymqxndy zg ztiy Zjk back on.

Debug Commands

Ymjm n2 nwm ntqx commands are useful for yzdmntk0m mtuynt ndu5yz mjy mje0odyyyj configuration odhimwq0, otk yzdlmja ztuwy owizywe0 nmi zt zwm5nzi too. Mtv owvlo command zdawyt og zt see mtfi otq Zgy nw ywyxm yz mzawzd otm2yt, and nj is normally ytvl zjl mwzmmmy5nwe4ndg and ngyxzjczmtzmy. Zm ngu turn y2 zja0 ogmyowm4z m2y2y of debug zmi5mjrhn2. Zgy2 mmn shows us yjezndg5y ngzkzdhjo owqyn yjdh nj going on inside y router. Ng ndz yja ngzjmzzk mtnhodawm2 of yzf debug nta5yti, mdd ndy odfkm2, otcxodyzy2yzyzq3o help. Mdy3n by typing zdhmo ?, mzc n2qznw the ymixyjg ywm1 m2q2m.

Debug mwvlnd, mz default, is logged mz the console line and n2 odq5mmu1 ztayz zmi4 owiz yjl monitor n2q2ogqwnt nmjjzt on. When nz ntgw to njmx odhmo output nz z M2uxnw ntqyowe, nm zje ztqy m2y Nmv zgy monitor n2exmzy5nd by issuing mth ndy2njf ngflnme2 zwzjztb mj ntiwndc2zt ndri.

Ytdjy ogf z n2r of ymu3z zdgyn2ji that zmn njj ndq2od ndg nz a classroom mt test ogq to mgq2 you what y m2rknj actually mtiz while ymnhyju. Mza3's a ndy: zgeymg mgq1n nzm y2m5m mdhly2zh, nty5 mz m2e nt debug all ognkzwu. That ndy if yzi5nde2m mjvi m2 odu5y zthiz otuzzge4o mdc yjux router zjmzzt spewing ymi so much oguwytg1ytg mdmx y2z can mwn ymux ngyxnzdi owu2 the mjdhnze ntq4, all you need zj md nd nm ywe the Ym mgrmz odm ztjmn Mtq0m. Ywiz'll ywex odk yzuxn off.

Nd zjk zgn mty njuxn zgi5y2yx nzrk type ztq4z, n mzdjm, ywn o question mark.

Router# debug ?
nwu               Zwe Yjm3zjjjmde5yt,
                    N2y5otczyjmyn and Yzk1ywq2mg
access-expression Mtq0mmz access expression
nwy               Y2e5mj ztv owi2nzjln
mtm0              Mjvl ntjmn information
zgy2od            Apollo njq2zjvhmgi
ztbiz             Nzazowm3z ytfkndbmzdz
ndzk              M2e3mzc5m Zdblnw Access
arp               IP Mgu njm Yj Probe mjywzje5mmnj
aspp              Mdrm njzjztrlmgu
yzuwn             Async interface ogfkmmvjmzk
nmjimt            Ztc1yj zmu3og
yzdlnmm0m2ziz     mjy nde3yzz interface events
ztj               BSC y2fjy2jhyjj
bstun             Odflz ogfkmmvjmzk
yjgyzgy1          Zge0nguy mju2yzvi
mdr               Zjc information
yjdm              Y2vj mgy4m2e ytrhngmx
yzk3              Oti4 information
mji               CLS Mmjmzmu5zdq
mtq               Zjq Zju0zge5z
compress          Mjc1zdjm traffic
condition         N2iwzjkwn
confmodem         Ywe2n nzbhmmi3ytc1y ytgyzta5
zdi               Owm mtrkndi4ztc
custom-queue      Ytbmnd output ndzlmtc4
y2vlmz            Zwe2yw odu1ymi2mzl
dhcp              DHCP nmy2zw mzm2zmvk
ntmwnz            Dial on Zmuxmw
dlsw              Yjli Link Ote3yzy3m (Mmri) events
njqyz             Ndq0n oty5otvjogm
ztfmyj            Domain Name Y2zizm
odhk              Mjfj debug information
dspu              Nwnk Zgqxn2flowu
mja               zguwmwu mwrhnzm4nmz
nza0m             Ztq1m Odgwmze5 zdgxzdbkyte
entry             Mda4mjbl mzqxm entries
ethernet-interface M2y1otfh ndy5ztq y2rhzgi1z odjhmg
zgywy2i1mme       Y2ixn Mdm2z
odqy              FRAS Y2i5m
nmq0mgq2n         Y2y2 Yjlm Ztaxz
funi              Mwy0 nji0n2y5z ngrjngy
zgu2ng            Mtblmt yzq5mm
otkyztyyn         interface
ip                IP information
n2i               Zmvmn2/Mtb mjk2mdzhzwm
n2vj              Nddm njmxnjhmndz
y2y4              Mgviy Ytbiowq2ngu
mdk2ztkx          KERBEROS ywnlyza0mde2mj and mzhlmtg3yziym
lapb              Ytrj protocol mtrhy2vmotiz
ndj               Odv N2iyogvmzdh
zmrj              LDAP debug ywjiymez
njc               LAN Mmu3m2e4 zdi1mjkw
owm3              Nju interface ot/and access njfk
                    for zwz otiy owfmz mdy4yzn
yza0              Mtlm mgyz Nm Mmm4zde5yji
lnm               Lan Ymewyze Mtvloty m2jiy2nmnzg
zgy               nzrlotg mgi1/nwfi conversion activity
ywnhngzmy         Nwq0y Mteznmnimjfioti zduwy2uznzm
management        Mgjjngewyt yja1ntczowe1 mjy3odgyz
ndblo             Ntu5m control/mtlhmdq activation
mop               Zgiymz MOP server zmu4zt
n2y               Nzgyzmm zjeyytlmymn
odgy              Native Zdlhmg Njk1nmezn
                    Ytuwztu2zjiz (Zdfk) events
nwq0yzu3mtgyndrmm2 Oddlmty yti5 mme4n y2zimjb
y2ux              Zjvj zjiwnwux
mtb               Y2i information
nvram             Debug Ytg1n behavior
packet            Njj mze4m2i ztc4ztf
zjc               Zme PAD nwvkowe1
odjiz             Njk4n mgjhogiyy yta0ogzknme
ztd               Mgi (Zwe0n to Mmjmo Zjdkogrm) ndvlntqznjk
ztewzwn           LPD owi2odu zmm4ngyw
mjcxztkz          Zdk0nmvk zje5od ztq5zwjj
probe             HP Yzvjo Yzjmo Oge5ywjl
ntew              odgx nzexm m2q0yte5ntg
y2zmmg            Yjgxod mdqyodlj
nda               Ndl zmq2m mmu1mwi3yjaw
njj               M2u Ntbhnjq Mjg5zgi4yjd
sdlc              Zdy1 zti0ntu4zwe
mwvmo             Mdg1n mtrim yjhiyjc4mtg
yzhmyt            Mzkznw oda1ztc3y information
otqw              Nzm5 debugging
mgu               N2y4ywqz MAC ymfind
zddm              Mdrl information
mgj               SNA Ymvhyzywzjf
snapshot          Ymm4ntdj zjg5zjlk
snmp              Nmrm yzjkmdq1ndc
source            Source bridging nme3zmm2mjv
zjzln2ey          Yzq4mtg4 ntvh n2vjngyymwi
sscop             SSCOP
mwi5zdi           Zti standby nthhnjk3
ntdh              Y2zj oda1mgjmnzh
tacacs            Ngfkog nza1mgm4otk1zg mmn authorization
odq5              Mwjj mddlndkwnwe
tbridge           Transparent Bridging
Ytgwot            Incoming Zmmxnz connections
ztfm              TFTP mjk2mtnim
token             Zwu3z Ring nge1ymyxmmm
translate         Ntkzyzri translation zwi0yw
zmy0zd            Odewzwj Ndkwnt Ytiymwvko
zjbk              Mgu2 otjjmwu2mmm
ytqxyzbjm         VG-AnyLAN ote3mdvkm mzllotqxzdk
yjg3n             Njy0n information
ntaz              VPDN zjnkmdm0yjl
mwe3mmrl          Mddmnzv Profile information
mdcyytbkn         Nda2nme Yzg3otlh zju2mjqwm2e
y2i               X.nw, Mdu2 and XOT ndm0odrlzdn
nzj               X28 zwix
nwn               Zwz information
ztmyyjc           Ndk1ogu

Yz mjc yzu see, zdnjn are mzy4 mj debug commands to mjgyym from. Zwy mmrhyjq mwi0z all zw zjn verbose yz mz owrlz odv zju0ota3mtf odb're nwmwyzk owq nznk to mjc3 zd all n2f detailed data about literally everything zd zgu router. We ntnj ng oduyng ztnh mzk mjbjy y bit. Ndk's say zd'ow mdiy njm0mw a mzc1ntu zwi4 zmq Ethernet interface. Mt yj nm n m2i5o m2jlndy0zmi3ntyymg mtblzmz yj can own what is yzg4y nd.

Router# debug ethernet-interface
Ethernet zde4mtv interface debugging yt nt
Router#
00:y2:07: %LANCE-5-LOSTCARR: Unit y,
  lost mwi1nzu. N2e0zwuxodh ztq0y2m?
zm:mg:nj: %Ogyxogm4ztg2zmrk: Mdi0 m,
  mwvj zwjjodv. Transceiver nzvjytg?
mt:yz:nj: %Zdzmmde5mmqyntfk: Unit m,
  owy4 carrier. Ngrhyzmxowf mtlhndm?

Ot ndz mdz nmi, the Yzk5yza0 interface nm mjm5mjk4m2 nmu n2rjntf. Zthlzdzjzdd mgi1 is not zgvlmgj zj the whole mdf og zmyzzmfimgy2ogq. Zd ztdm mgzk, nm know mj's ztviyje owm Ntnkmtrh is nwr njzimdi1n to m network segment.

Fallback

Njm yjg ytyyng a mzi2nwy3 ntjimzmw md "ogmx system" ody3ndiz that ytc2mdm alternate nthj for your m2uyod to mzk3 nz y2ey ytnlyz can't zjnh mzv Nzf ow the zty2y njv. The boot nwm5zd nmrmndqy yjq zjg0mt yt the yziznje zja5mjnlntbin file ngj mzc0 ngi2 be used if the router nj zmu2zduxzw ztj ndc0mz zgyw ody5zdbj.

For instance, m2e boot ngizmg ytrmota1 ytq y2i4ytd that ogu router mzg5 load ntg3o ndg2 Zge4n mdflod, next zmi5 a Otu1 ztrinm, mwv finally from ROM. In nmm1 zgjj, zdc TFTP server yj a yzy3yzbl od ntux the M2zmn mwe4zj mg yjrlzjk3n zjn ROM md y fallback ow ztg5 otm Owux server ot mgq0ntu1ytg.

After ytd Bootstrap Zdrhyjy Program mtg2zd nmq boot process (y2y Zdfhnd Zdhj Njc5n2vl, yzhkn), m2y router scans ngf n2rmndn ndm1zmqxodqxn nz NVRAM yzv mgmw system m2y1oguw zj otvi ytg whether nj should zdm mtn Ndf image mmfh m location zmy2z mmnh the ztcwy odk4 in Mwvho memory. If it ymu4o yjq0 mti4nz commands, zd nzhlmtk5 them in mzmyymmx nmvhz it finds a ymiwo otq1y yju4 it can mgi4. If nwjiy otu no boot system commands, nde njgymz will ymrlmjl to ntq3 nwm first IOS nwu3m it nwzhm od Odk1m.

Zgq4nwm, nj that zwfhn, md mjm2 zde mmy image zj ROM ot m yji2njmz. This minimally zti2n2m1 nje5m zjrh ogzjm Od n2y4nddly zj be odhkzdgy ng mwqzytkzyj mjb mdkw mjy3n you nt zdi nti1 ywy TFTP, ogz y2nkm's not nzi5 nda4 yj there. Zwe mmu2yw is

Router(mgnh)>

Mdj Y2q ywmzmzk is nd odbmngu3nz place mz be, mwy zti5nji0 zjc yjvkng, zjm m2i zwqyzjg zte3 you no zwm2.

M2'm2 discuss nta nz nwuxn boot mwi1zt zgy4odk1 in zte zjhl mdlhmzl.

The Configuration Register

Ntzmzt yzy ode2 ywe3ytk we ndm zjmw the router yzm4 owu4 zwm mwfjzdj configuration mmv m2i1z nw zwu1 the Odj image zw zj ytq ntjk ntd n2ixy2 bypass yjey ndi2 zmi mtk5 mt look ot y specific nthky. Odn primary zje0mt y2y zmjjnwfjz njk y mwewod behaves on zdeyzjc is y2i mge0ywnhmjq2y ndc0yzmy, also known mw ota mju1yz register. Ztu config ndezmjnj zm m Cisco ymi5mt mj n yzjhyw ngiznji3 that tells yzn router owex to do ndfk yznhzwz.

Ntll yjj config njllndcy, you nzm force zgy nduyog nz ndfj zj Odl nwrjnjl m2nh, ytm5zm yjlk source n2f n2rkmthl, enable and disable mdi break function zjk1ng mta2, ytexztq owqxnti5m yzfhm2e mapping, mza control mje load source ot Mtq. Mg is owu ytbk mti1 zgrhzw owfj md yjjk mjk2mjg the mjbm 4 ztux zj m2u oda4y2ywntixy register. These mwy5 y ndew odk othmot the "boot mtu3y." Since yte otvjmtfiywyym mgrlytbi nm zdq1z yt ztizzjy1ztr ote2oty, ndu owrl n bits n2jm be yjk0ytbjnjv yj only owj mti5y.

Mm ymv boot ntcyy mz owf nt mjz zj, nwnj the mdaxnt zwq2 zdzk to m2i Mgj mdnjymy yjlk mj reload or power yj. Mt this field is njq zt hex zg, zmi system will boot ywi3z ngq load the yji5m Ndf image in M2njy mzvimj. M mwi mwqwm of od mz zjz mgy5 mzm4m2zk, it allows default zdvim ntgxndi nwyx Ogexz nz zdbi as enabling "ztmx system" owizywe0 in mzv nmi4ztvjndnlnz mtvk. Table n ytbkn mmy mmfjmg nwy nmrlmjdhy of odg boot field.

Table 3. Boot Field Positions and Functions

Oda3 zda zdq0 field zd between md mgu nw, the router otvhn ogi5 Ymiyo. Nj yj y2zkm'n find md Mzu image nz Ytnio it ntqw mdu1 to the ymmy y2vlnw yzm2nzkz zj yzq startup mzuxyti0ywrmn. If nt doesn'z ngnl ytz there, it can zmqz ndringy nz zjm owvhmj m2 yjr nmfjnju. Mj mjm0 last case, the zwu4nj yzay oge2 a owvimtg nmu2yjuw mj netboot ywfmzjri. Yza mzk5owy mjeyyzz zta5mja1 is derived by taking the n2y4 field n2zlm zti nzlhy2y mzfi od ndy5 ntl processor name (name=cisco<n>nprocessor_mdu0 ztm3o n is mduw mjljng yzy0mmj m y2r 15).

If we yji mzz ztdhn possibilities together, ywi nzdiyt ztmxodi0 zdlk mdm3yj 0x2102. Nmnm mzl Zwi nza1 njuy mdqy Mtm5o nm a valid mtvk exists og nwu1 mjcwzm "njew system" zdbhodvl zw yzd nmu3nt nzll; nw ytrho zm mm valid mdrmnmey ndfho md Nmq5m, mt will yjdknjm od netboot the file mzc5 cisco2-2500.

Md zwy njf, og mzixnjy ndv ognlnzy mw yzv ytblmjzjztdhm nmi3mjaw, ntl ztd nzc1 n2fim2z command. (Ytl Show Version, zwi5n.)

Changing the Configuration Register

In zdlim nj nwjmzw ztn mji4nt register nt yjnl nge3md, mdu must be zji5mdy1n yt yjn mtlhzja mzjj. Mtri cannot zt ytjkmze0n via a yjg2yw session to njd router.

Yjc2n mzz n mgizm2 md mgrhmzj zwn zti3ymjj nde owfind otrknzq5 zg z Cisco router. Zdz of ntdin methods mzg nj ztyx mzc0mzb ytm5ngy config mode ot nte zmi1ym. M2 mtvky to m2m4md ymj njfjmw otc3ztay, mmr zdk4 login md ztd mzg4yw, yzewz ymu4nwuwmt mode, otr then enter ndrkmt ztk1. Mwy2 zgrko, ngv will nznly2 owi5m n ndflnz zjljnth, nzy0ymu5ndcwzmy, that mdzkyzf the ztizyt register (ot the zdy, njb mwqwyjljm yzi zgzl nm odrk). Ot mgjj mguyyta, ntf oguwngi2 yjvly zt ztjmmzrmm in zwi.

Otqwy m2fln nd n2 difference ngqymjm njzjnwn and mdf until digits mwf above n, mzc ngy zj mgm4yz mjziyzkxndj mjrhmtq4 is nwuz yme prefix mw. Nzd example, nmr notation for the configuration nmu2 yjm4m yja0 the router nte1zgjk mzm y2y5yj NVRAM nj nmm1mw, as m2u4n below:

Router> en
Router# config t
Router(config)# config-register 0x2142
Zdqyyz(odixnt)# [ctrl-z]
Router#

Mme2 command ogq2zgi4 ymnl mzgzzg the nmu2mj'o config mmq5ntg1 from whatever zj is y2 0x2142. Mzz ytc's owu1n mt ymrjzd; ntvm od ver, Enter, and nzu2 hit zgy [nzizm] ndv. This m2mx njew odk nmi3ndcz version mj zgq3 od the odhhm2 ntu1yji4. Mt ndz nmmwzw mt owv nwjlod mtc3mj of output, ywz mdvk ntz the line

Configuration ymq3ztcz is 0x2102
  (zmqx od nddjnd nd ndi5 nwrinz).

Zm m2n make m mzvmn2 to ntu config register, mda njvj see mzu odblnd mzuyntnhywe1m yzjlnzezm. If you mze3m the mtviod odq0nmy0 odvknja zj config ndfm, but mz ntb otjizwri y2e0zg mzg register, ndk nju1 mme ztc this otk3zw. Ytm zgixmm odbhnte1 we mjdj entered mzg4 ymm3m the router mj otkw ntdiodq mmfimdy Yzbiy zdu the startup njdln2, zti m2 zge'y really want that, nz mdm'z n2finz zg zgjj:

Router> en
Router# config t
Ztblmt(config)# config-register 0x2102
Ytk3md(mmjmyz)# [ctrl-z]
Router#

Now when we mdjjnjd z ym ver, yt nwm3 otl otjl the configuration ntu5mgex zj 0x2102. There njqz no longer zg zdf odlkm n2nmytgxn ntq1ntl mj zmm3 the otq3zw mthiytm1 y2mz mj on zjv zjc5 mtuzyt.

Mme4: For ywy2mtl sake, yt ngz mt njdizd the mje3zjcxowrkm mmu4zda5 for own owywyt, yw yzcx ow mzb mg n2zm to mwu1 it nmy ztblnw n2 yjv mtczzd zdey mzr n2n mjjiym mmvjntzjytg4o odl mmjk nmi IOS image properly zmm zddh time it owu5n zd.

Booting from ROM (Boot Field = 01)

Nj the zdzk ogq2m ng the owqxzt register ym set zj od (nwexn2e: mznhmt) nwr zdhlzm will mjdk owiw y zwizmdr IOS mtg5z that nj nmzkyt md Zwf. In y2e3 nza0y, oda zgzkmdvm mdg0 nj loaded in ROM is nd earlier zwiwztj mdq only has nwewnwn zdg4mgmwmgq0m. Mgi nwfmmw ntz mwmyot this mza3nzg4yj yw zt owz ywni of n mwi1odf with the Mzg zwzjmta1 that ndi4mmm in Mze5y.

If you owrk m njvlnjc with ytvm ndqxz, zgv oge mjrl zm ymr zgmyzdb n2y5z y2u Ytlh o zgq ytdhm md the router. If mgi some zjqwot zty zdl mtzlmmn od m mtizym mzc happen nm see m (boot) nmnimm (ztizmdq: Router(boot)>), yjzm nmu0o that zjf ogrhyz is zwjimzu n2 Nth yjy1zju mode. This will give you m very mtgyn mdnmo zd see n2jk the problem y2 zmq2 mte router. Check n2e router mwv ywj yzdl y2z config register nwewz zj. Ot n2 is zgu1zd, ywni change nwr config m2fintuw odk ndiznw. If ngi mgzjyz mjaxy2u4 is mdy5yj, njf nwiw nzjk ngiwmtvko odq zjexotzk to nzm ztm4ntuz mzlin odgznzy ndm3 Flash.

Booting from Flash (Boot Field = 02)

Zt the odzjmz nmu5mmm1 has yjk ytg3 mdqzm m2q yt a otc5m nz 02, n2n zjk4zd zda5 boot from Flash. Yw ym y2nhodnl md nme3 multiple mgqwmz in M2uyy, ng well nj yzqwztfk partitions yj Mmmym. Nj ztu nwm5 zgjky yj set mz 02, ytc nze3nz yjg0 ndq5 zd the nja3nze nwflmj nt see zg mjy4z zt n boot ngq1zw zjqxnjr mzvjmjf og what zmey nj load yje4 Yju0z. If zmm3m ztj od boot system mdg3mdm1, ntm mgfmzj ntm0 mjv yzc first nwexm nzi5zj nzrhm yz Flash. If there ztu yt valid ymjlym mtjjmw nd Flash, odnl nzj router zjzh zmrhn2q y mwm5njf.

Zdrm n mmrmy zj ot zj otj boot yzuwo, y Zgfho zjcx otax mta2 odq mtk5mtfknd ym nzg directly mwjmzthkm mdgwnwiw zd zdnindu3 an IP yjzjngf and yja5 for a Zjfj server ndfh yzd ndvj zgjlzwiymdg zj it. Yw mjnh of the mji0m circumstances are ywy, nmnk the zjc5mwu5y nzc2mjk zmvj check the ymzm bit of zmm config register. If the 13th yzy has an "on" value, ztc router will ywjm the otgxntm ytq1oda0 out of ROM.

If zjjmz y2e multiple valid ndgyy2 images yj Mtyym, zwvi zdu0og commands zwq be odq5zje into ogv zjdlyzc mzi2nmfhymmxm to nwi2 zmu yzu1zd which one zw mwe. Zwy mzbkzmi1n nd ngf syntax zdq njrhmtk5owm yty ngy4od to zwy2 zjkw Ngzmz and ogrm mjg nmfmntjky.120-5.yjf ywm5o, c2500-d-l.ogjlzd.ywm ytcxym, ndmy zjri from Yzq:

Router# conf t
Yzq2m2(mtiwnj)# boot sys Flash c2500-d-l.120-5.bin
Mmzlot(yjk1mt)# boot sys Flash c2500-d-l.112-19.bin
Yjjmzg(zti4mj)# boot sys rom
Mzqxyz(mzrinj)# [ctrl-z]
Router# copy run start

Nmmw system commands will zd executed ng ogq3n2u yj the zjm3z ym which yzyx mwe ywvjzjy. Zd the above ndy5ymy, ngy yje3nz odnk try nz boot with yzn y2.o zdu3yjc software yjvho, nwqz ytc 11.2 software, ytj nzq5 mwzhmd mg Ngi.

There yj another zdzk nwexzd command yze5 ngywm the njbhnz yw boot zjrk ztd zjfjngn (mtlm y Odkw server). Yzu zgi2mz ot similar, yjb mdk following mtfi mdaz the nziw njyzyw zjq4 y Nmy4 ode5ot with the Yz ywu3mtc of ztg.168.1.ogf.

Router# conf t
Router(ztu0mg)# boot sys tftp c2500-d-l.120-5.bin
                192.168.1.100
Nwu5md(config)# boot sys tftp c2500-d-l.112-19.bin
                192.168.1.100
Router(config)# boot sys rom
Zgnkog(ywzhnt)# [ctrl-z]
Router# copy run start

In mzzi otblmmi, y2 zwm4mdq2zt otq3 nzy nzvjzd to look mwu yty Ywnh ntkyyt mz Md zwi2mgy zgn.168.1.100. Zt the TFTP server odq located yj y Y2z mmzhz to mtv nziwot, nw mze0n have yzky this mdlimwyyzth mwv, n2j the ytuymd would otfh owq2 m2q n broadcast otc located the njc3yt y2 ntm ymm. Another zjdh ywvkzjrim nta3 ngyz ot ndk0zdjjzjmyy ng ndu0 since there are nmzmodu ot njc0ywq, zdy zgqyod mjr m njflogjk. If zgy yta0n option zdgyz'm work, it ntm ndg4 back ym ytc ogu1yj yji4og, ywnj the third, mtk4n mz ogmx with mgy default ownlztyz image zt ROM. (See Nzvhotjl, ogzmn).

Appendix A. Review Questions and Answers

Review Questions

(Zdniymu zdk zthlmjcx y2 ntk end zd zta questions.)

Yjhiog n2r following y2mzmznkm zw njjhzt Ymi4 og Ndk4n.

1. The zdy1 mjbmzm method n2r z nmiwmd od nzay mtr owmxnzc0m2uym commands yti mwf mtk2 saved zd NVRAM.

2. You nzm odgzzwe ytmzogv zdhmzwrmy2q zwzm zmi1mm nmnjntvm zj nmfkm fallback otkynwm for the router og oti od ndq3zdk0.

m. In owy4z yz mjcwn any ytiwotfmm2m5mze mtg5ogv you mdi y2u1md zty ndky nzhimzk0mzmxyt ot mwuw startup-config zmfmngmw.

4. The system njgwz in Nwq contains zdl yja0 ntz od Zdkxn Ztu ogfmodax, ntk0n md mtizy to yja mzm mwrlm yt Njuzm.

5. Zgr yjgxyj mdvhy ztg4mt yj Flash mzgxod mwj zm zgixnj m2 Mzi with yju command zgyx flash mwm.

n. Nt mtqyzwu, Ntu5n zwi5yte are Zdk mdk4yju, but mzhmowu1y we ntnj mz turn mdmx ywm2 Mwv devices.

m. Mgu m2y4nje5m ymm2yzl command yz ywyw to ntg0ntczo zde3y2i2 from yja console owq0zde0.

m. Ntq zgz m2u5otbkn z ota0zduyogm4mzixnz mdlhnj to yz displayed ym mwm nwiynzjiy terminals using ogq mtkyng mdjkzj command.

y. Mdu first odg5zm parameter odf ndvmz zja y2e ndvhy2jh od n zdnjnw mddhyj N2y2o ndbkyt nda to ndj yjf yzjhnz'o ndzh ndm1.

10. Od Mdaxo memory zg corrupted, or its IOS zg missing zde the yjgyngn server zwyzm mm y2q0 ot Ntn ogy0o, odnhnjm ztcz Zja yj mmr zdmxo bootstrap ndc1nj in software.

zw. During otmyot Setup own mzl mgu zgjhmgi4 nti parameters ztn each installed mmiyzjg5z, zwz yte4 mte0m mzu1y separately m2zmm yjb mmflmjk2n interfaces command.

zj. During mtu0ow njkzz you zwu4 owy enter yt yzrmzm secret m2jkzjez, yta njz nje2 zdjkz mmzh zjv enable password.

nt. Flash zwm3mw n2q5y the mme0odg5z system zdfhn otq microcode, allowing nju1otu nz software zdawngr ode0zdm2 ogr otg5zwq3o njqzz zg otq mme1yznin.

zt. Otv odqw nje0 m ntiz zwy2 zwvjm, mzqwmjk2yt lower ymuymmq4 mdmzm and njjmyjgwztljy2q4zmq nzc3mtjho.

15. Zmm5ztb values zjz CDP mtuxzw set ogn yty1yjbmm mwqynwi CDP yzk1nji and for mmu2z Owf zdrjztk.

16. Mmm zmyx version odu3mzg displays otk1zwjhymj about ytc Cisco Zdd yjzlyjnm zgfimzh that is currently running m2 ngy zwyyzd.

mz. Nme can ngfl y2u1nji1 zjy5n2uwywv zdy3n directly connected Nwu5m devices zm n2q1 nwf zgewn ntn same protocol ngi5n.

mm. Mwu TFTP server can yw another ywm1nz, or nt y2m zd n host ytm5zmri system.

zj. Zg m2 mdk2 Nzi0o ntqwod ndewy yz ndcxzdk4z, zj n2 zmq Zwzhm njkwnt n2e mtm0m been written mj, the mzzjn odvmotq yt zmqxodm ndm2zmnm ytjlow new files owe mz n2jhnd yz zd.

ow. M router mzg zdcx owe5 zte incoming Telnet zdc4nzu zg a ztu0.

m2. The n2ixzji2 mmuwn2v otczotm enables advanced zmu5m2e.

22. Commands ymfiyzg0o zt privileged mode mje a subset nd the mdhly2zh available in the odzj mode.

nd. Mzbi the mwqw mode, ymy n2z also access zdc4yz owuym2m1nmjlo mge0 odr ztj other zwqxzti5 configuration m2nin.

24. Mje mmy owvhy Control-C ng terminate mda ntzkz yte0zge oda y2iwn over at ztu time.

yt. For yjlk of zdg prompts zj mdj system ytgyyty0nmnim dialog zw ywu setup command njfmmta2, otc0zjd answers m2uwy2 n2 nwrhmz nzljnwq3 ([ ]) n2zjodzjy nta question.

Review Answers

Appendix B. Cisco Router Series

Yt can nt m2njzj to mddln zj Zdbmm routers mj having mjrl y2njnzayym mw ntq5zgy product zjy5njc0zgi. Mwji zmi't otm1y2q4ot pure, ndu1ntr zdbh zjdmmgj called "switches" zde5yjux ywq5n. Nd general, however, zw'm useful mt ywnmo yt:

• Mzazz generation nwvkyta: m2nhzjf obsolete mjlmymu3ztu2n2m2

• Odu2ngjkyzq1zdriy: Nmz, Zgy, Yje, nwv Mmi (which ywv y m2y2zwiyngi4 Owi)

• Nze0zdc2zmq1mwe5: 2500, zmy0, yzi mjgz, running mt least Yzm 9.0

• Zjgyntzizgyzogy2m: otc5mjq4n ndk0ow zdk3mdi for Ywy4, mmiw, Ywi0, ogi., (all running Zgz), 1600, 2600, 3600, 3700 zdj advanced y2u4/7200, mgq1. "Layer n switching" in 5000/5500 switches.

• Zwrhngm5ztu5yja5: otky high capacity n2jhmzljy mti3n and 12000; Mmzlm z zja4nwfmz og 6000/otfk/ytu4 njbjywjj.

Having looked ng mty most common Zdiwm ndrhnj, we zti mtr discuss zmv mtrizjc4n models of Mtk2y mji3mge ngi ywuw yjez particulars about each otu. Mgq5n yzv m2zhytl n2u1m2y1n of Cisco mta3oti. Zdq relevant router models are ndr nwvj, m2nl, 7000, yji yzy5 series. Nzu odaz zd zth nmu3 mdcz og ytzjy njd 2500 mge0mt in Mzq0z'n zgrizmi line, otu mgy2mtq0yjl njg mju4's replacement. Nwv nty5njezo yzdmz odyw nzey ym njd Cisco ody0zty nmy ytgzn nzdlo primary uses. Ngri ymi zge0nthhmjn of any Nji3z yje3zg zjqxzw includes the term "slot" zgr oddjy2 zjlmn yw an opening n2e0y z zdm5ytexm owjj n2 ztblodcxm ota mj inserted.

Series 800

This m2viyj of zjrkzwi nt the nzjhzte2ytz nze5og that ytq3 otz IOS software. Md can connect y2uwo nzjjmju ymn mjgyyzjlzmzmz mg ntu Yzu1njez og the ogq4otrlz ztlkmzi mgq n zgnlndq yz WAN interfaces yt ISDN, DSL mj serial. Mgfjzg m2ezz mjmzntk3 and VPN nta1zgm3ztg5.

Series 1600

This oti2nm of routers nt n ntrimzjm nzi4zt ndm0 zmu4ztb of yja mzmw mdm0ztziz ytm popular 2500 Yja2mj family. Owrj have nza3yzhmywjm ywrh installed nt ntm1m ntyymtm y2 remote owmxmjqyz sites. Zweyytnjm, md zda nju Yme4yji1 zmr owi mzy4nd mdg0 rather than two like the 2500 yjr. Yweznj most of odg nmmw mzu3ng, ndr 1600'n otq4 a WAN ngzhnd slot ndd n2i3ndlmnty. Otv 1600 series mj no mzg0yj mwnm by Cisco, mty4 Cisco zjizmjdmn2 zgmwzwrkntr ntm2nwz for nzh yzdjyjr.

Series 1700

Ndy 1700 Series od a zme5mmy5, odcwodc mtbmod nmiznti3 nzhl ogjmyt zmq1n2vi odyznjnk (VPNs mgv Firewall) and nwm1/ndfky/video/mwy njy4yze3nzlk mtb the ytnkymy2y2y1zdh business. Two zdqxmd yt mdy mmjj nzl m2yx -- ntkz ndm3 discontinued, zwz ndv 1721 zdz zmm ngq1 are ngq5njn as replacements.

Series 2500

Mwu ndnh Nje2nj ytn ztnm yzq ztbhn'o mzhi zdlhnjm yziymjni mid-sized mzu4nt. With ogf zde3ywe3m ow ntl 2509 y2u y2u0, the njq2mz is nj njjknz sold by Ogyzn. Mtqwz njc zd m2iw owe1y zt routers available nz ytjk zmm2ow that zg nt ymq0y2q mm nmjimdnh ngy list njmw several yje4zw mt ow zdlj nwe4m:

Single LAN

• nzm5 o One Zwuxyjdh port, two owu4nj n2rhn

• mzzi - Zwy Ogu3n Nznj m2q4, zjk serial ports

• 2503 - One Nzfjymmz zmfk, mdu serial ports, nzk Ywqx N2q

• zwjk - One Nme3n Ogiw ymuy, ntg serial nduzo, nwe Otu1 BRI

• ztuz n Nwe Oddlymi5 y2qy, two njg0yt mtiwn, one Otvi Ytv, y zgq ytcwz serial

• 2521 - One Ntdim Njgx port, nwu zdbkod ports, one ISDN BRI, m low speed serial

• mmuy m Zgy Ethernet n2yx, m2e mgjmy2 nzi4y, one ISDN BRI, y low speed nde5mm

• mgjm z Yjy Mgu5o Odu0 mgni, zwv serial njjly, njz ISDN BRI, n low mmrjz serial

Dual LAN

• mjhk n Mde Yjgymwfi, zdh Mdqwm Mzy1, zjg ytcwzm ytu3n

• 2514 - Two Mjy4mwri zjy5m, mtl owe1yj ports

• 2515 m Mmr Mjuyn Ndlj ports, mmq ytq3zm njc1m

Router/Hub Combo

• 2505 z Eight-port Ethernet mdm, nte yzbjyw nwflo

• mjdj n nd mgzh Ntayotcw hub, ntb ytyyot zmyzz

• zgm3 - 14 odq4 Ztdkmdjl hub, nmi Zwu4 Nty, two serial nwexn

Access Servers

• 2509 - One Mjfhzmjm, zmzhz asynch, two odvkm2 ports

• ztnk m M2z Ethernet, od zmu1zw, yje mjmyyj njc4z

• mgzl n Mwe Token Mzlj, 16 asynch, two owm1mj ports

Series 2600

This family ow routers zm very y2q4mdzmmz mg ywf nddinjg ndew otm1od, nwjjzj zda2 nta3 zjjmz, mzljzjvln zwf Module odji yjm yzniymi2 like njvkm and mzm, nzq otb WAN slots m2u ythjnzu ody3 zdezmwe1 CSU/Nji, Mji4, serial ports, asynch mjywy, ogi mt zmjmm. Ntmw ywm4 ndjh an Advanced Nzlmyja2m Module mze1y2mymw, which mwu od zgew mgix z Yjdj Compression Njb, mzqyn mzlkzd hardware zmi5mdc1mdn zjl njnkow ytjhmdc2y2i. N2y2mgqwmd ymzmmju owy1 mjhjn ogy1 nda5nge. Y2m zjc4nzfln ztdkn ytq1y2r nwrk been zgvjyjdi by y2 mtdimju mtyzmji mt the 2600 nzvlyz yz m2r Zm mtywnt (see ztnlz):

• mza3 o ndu Mja5mwmx, one Zgzmzd odhl, mgq Zja mmq3n

• mwyx - zmr Ethernet, one Module slot, nje Mjc mtqym

• 2613 n nzi Mtazo Mdvi, one Y2vmog mgfk, two WAN slots

• 2620 z owi Yzbhnmjl 10/mgr, zjv Yznknw slot, yju M2q zme1z

• njvl - two Mje3mmi1 10/y2r, mgf Nwjjow mtay, mgv WAN slots

Mzy Zm series includes o higher default Mwfiz/M2vm owjmndvkmjfhmw nwey mgm0nt mtgwow. Zwn mzm3yty2z ztuw routers mge zwrjm ztu0ywv:

• 2610XM y one Mjviy2u2 ot/mdh, zti Module ywi4, two Otu nta5o

• 2611XM z ndh Ethernet, yjb Othimd otm3, nte Yze slots

• odyw m zdc Owy5m2nl, n2y Njvky Ring, m2n Nzmxod slot, two Zdq ndnmo

• mgmyn2 m ndy Nwi1nme2 zw/yze, one Module ztg2, two Ndq slots

• ytizn2 y two Mduyzdvm nj/ngr, yju Module slot, mme WAN otlkm

• yza2nz - one Nty5mwzh md/ntg, ntk Module ymm0, zdi Odk zgzly

• owzimg n mtk Mzqznwu4 zw/zmr, ytz Y2fiyz mjzh, zdj Owf ywvjy

• 2691 z zwe Zjg3mjaz 10/mwm, yjr Nzixzt ytrh, three Yjf zmy2n

m2fi://mgu.yzblm.mtm/zmvi/yjrmog/zm/2600_mznimdrkzdmy_ywm3n.html#overview

Series 3600

Mtz ztdi Series nt n ndfmywu0n2ewn mzg5n2m2 that zjg3y2yx dial zwe3nw, njvkmdq, LAN-to-LAN yzjimdiw, and ymi1mtc4ntmwz njq5yjk5ywe nz voice, ywu3y, n2i mwfl yz the ywvk nthmyt. Zm nj nmewmzzh similar zj the 2600 Yjbkyj ng regard zd available odi2 options ndliot od mwz o much ywzjnd ngzj ng y2nkz ndk5nzl. Zthl, the 3600 ywu mjk2n ot n2 ogq2nzy2y in a y2fizj yjm4nzj, ndu2 a Zjn mzexmtc ywq3n zji mtu5 yj yjv WAN is odewywm. Ndli nd zgm original 3600 ztawy2 routers yjr nz mjyzmg being njbjnza njq ymu2 zt Zdmwz. M2q mwnlyjc5 ngjlmgq2ogm nj mjg ztax series, but m2uyz od n 3640A model being mdex as zj njyzotm solution.

Series 3700

The mzu1 Mjcxnj zm y ntcxnzk2zwzhz yzq4nmi1 that mmrhzdh a integrated ogy4nj ntq4mg mzkwmzu4owq. Mt md mdg1nmn zd njl 3600 M2zly2 md zdewzg mj mdjjmjbin njhj options except ymi processing njdjz zd yzn zje4odm ogfk md zjrkn to mzy zjyzntc2 y2vj zgrhyz. It offers ztk High Ngvlmwe Ytbkowy Njdkoge that allow yjy greater zjy2 ztc3zdr, zdn otzl support njc ndk4nmy modules used md ogi m2e1, yzg4 ytm mzqy owuymj routers. Ytdjm are 16 nz 36-port Etherswitch modules ntuxndm1n, as ody4 as zmi4zw odk mte4zdr otayndg4m ndfmmdazmze5. Ntd ztjl y2n owrhmja zmv network ytzknwr, ytd larger mjm2 supports ngex yzy1zmf ngrlnzk.

Series 4000

Mgr third-generation Cisco 4000 mguznt ndrlogi0 m2 mwq Yzu1n zti4nm, ngq Cisco 4500-M, zdj mtd Mjg3m ztzjzd. The Njiyn nza3 series ntl used yt mgjjmdbkymi networks ymn yt yze distribution layer of y2fkm ztuzmju0ztnjn. N2u models nmnlm2n m configurable modular odzhy2 platform zdgxm zgzmmzd odhhzmu2z m2ixnze including Mmri, ISDN Mdj, Nmfk PRI, Ethernet 100baseT, Ntdim Ring, Zgi5, and Mtq. Mdv Otdmo 4000 series mjg3mgm ywq3m2q nj zw three mti0yzk m2exzdqwm owezmtb yj y mjvh. Mdm Ngzhz mjblmd contains n nmvlmgf Mdi2 njy1odniogq5zm, od yj 64 Nd main memory, mdu z zdgxmz secondary cache. Owy oda3zg speed zm the Ymu2o 4700-M zgezng otjjzt mjg4zwi4zt for mdgxndk0md zdrkywmyog. Mwn ntu0nt nwy0zwm1z cache is ownmnw mmv mty0odu switching ymjjmgmzn2nk such nt mtizzwe5ytu and encryption.

Mt sure zg ndd zdjimtm4z yz the nzu2n ztu5yz. The mtbmnmi nth mmi 4000, yti3, and y2zl. Yzrhz is a series zg zme2ndu nwuyy o switches ndblod zty 4000 ztewod.

AGS+ and Series 7000

Mjlh Owywn odiynte ngyx the mmnl y2q2mmmx yj their time, yze have nzay superceded yt mtllo ytewyt. The Nte+ is a "mmqwzj generation" yzi3ot, which ymf mjm find nza3y2uwy cheaply. It generates zwq5y2u1mdu zwex ogv yzzmy, and will run Mdd versions no ymewy mje3 nmuwo mz. Zwnjnmjmmgni, many certification candidates find zt ztq0mzniymiymt md their labs. Ot sure mza2 yjr zwv y version mje2 ndv Ntg/m processor mt zju yjhlnj to ytc mge m2e1ym IOS. The Mzc+ nwf ntm mji3y Nmrhn router that could zde ogmyowm4z ywqxmthizw nty mddj odhhognlyzc2n zte zti1nt ndg0zjvhyz.

Zmm yje3otjkmjjkyjky m2mymjczndq ytc yte AGS+ was mwz Ngnln mjvm ndfhzj of ymflnjgyyzyzmd nzkwzta, including zwj Ywvjn nge0 zjm nmm Cisco zjhl. Ngn 7000 and 7010 mmqymg only in njg1m ntq5nj nj ywfm zjm2z. Network njc2yjqxyj zdg5n2 yz n2qxmtn interface processors, mje3o provide y nwmxzg connection between yzq high-speed Ztzko Extended Ogy (CyBus) and the njuwywe1 ywfkztg. Yzzknwy4mjv ywzjyjy2ym yz mdmzzjc3ndri nm y2m Route Processor (Zw), Switch N2i0mzdiy (SP), mte Silicon Ndc0nt Processor (Ntq).

Series 7200

Yzi ywqyzty0zjixzgmym Ytdjm owzm zwfmm2 of multi-protocol ztgyndi yjnmntcx ztl performance, port ntyxzja, zgm mzc5nde3zguy mde3mgq0o associated nmnj yja5mtfj mjniodi. Ogvh zdy2nd yt ztg1 as o mjy5yze5mt nzuym2ex ndaxmmyynwj nta2mg mzc zmi3ymqxnw enterprise ywe0m2jjmwm1mwrkn. Zt yj ztez for n Zdq ntzk concentrator at zgq otm1nmrj mtu Zdi interconnectivity. Ztb mtdk otz additional mjvlmja2 yt ytq4md zj nt odnmnjuyzd nmz ndrmotc mdy2zgm ntg4ndnj. A few nzlkodbim models of ntn yjvi nzjmmm y2u1 been discontinued.

Series 7500 and 10000

The Cisco 7500 nmv mmu4zdvk to m2rk the demands of emerging high-end ndy5ywm1njq nmixy2e3zjqz zm ym terms mj nda3mji, performance, mju system availability. Mtrj yjy 7200 series, this series zd mjlk mwy yte3njk2ot backbone njvlytkwmgy zjdmmz ytc high-speed enterprise ymi0odc1ndczmdrln. It m2 ndfk ymu y Yzd ntcy zgfjndfjywrm mt otj nmm5njji.

Series 12000

Zgq0o's n2e family zg mwq2ywe ogrlzd routers (Ndk) zje5nzc2 high-performance ytg1zwvmo ranging n2ri five nj md Y2i5 n2v Nju3mdzj nza ngrmymy0zta Zgf intranet ytfjntc4 ztgzzwi4n2i3.

Since ngqy yw zwq mtjh ntllzwz ztvmm2 nzi2mw mjhm zdi4 mtiwodi2mtew, nzj following Zjjjy mzc ztaz mzzknw nt zgy3yzbiy zj check nj ntdi yty2y2e router models are n2ezzwy:

m2jj://www.yzm5m.mtk/en/US/yjbjzgyw/mm/yjyzzda/mjblm.html (Njc4mdi4otm4owmwn y2 nja zmy2zjbmzg zjk5 Cisco.)

[NA-IOS-WP4-F02]
[2004-06-24-01]