© 1999, cisco systems, inc. 5-1 chapter 5 managing your network environment

© 1999, Cisco Systems, Inc. 5-1

Chapter 5

Managing Your Network Environment

© 1999, Cisco Systems, Inc. www.cisco.com ICND—5-2

ObjectivesObjectives

Upon completion of this chapter, you will be able to perform the following tasks:

• Gather information about neighbor devices

• Gather information about remote devices

• Create a simple network diagram to document the network

• Determine the location from which a configuration and IOS image will be loaded


Cisco Discovery Protocol

Cisco Discovery Protocol

• A proprietary utility that gives you a summary of directly connected switches, routers, and other Cisco devices

• CDP discovers neighbor devices regardless of which protocol suite they are running

• Physical media must support the Subnetwork Access Protocol (SNAP) encapsulation

Upper-Layer Entry Addresses

Cisco ProprietaryData-Link Protocol

Media Supporting SNAP

TCP/IP Novell IPX

CDP discovers and shows information about directly connected Cisco devices

ATM OthersLANsFrameRelay

AppleTalk Others


Runs on routers with Cisco IOS 10.3 or later and Cisco switches and hubs

Summary information includes:

• Device identifiers

• Address list

• Port identifier

• Capabilities list

• Platform

CDP

show cdp

CDP

CDP

Discovering Neighbors with CDP

Discovering Neighbors with CDP


Using CDPUsing CDP

SwitchBRouterA RouterBSwitchA

10.3.3.2 10.3.3.1 10.1.1.110.1.1.2

10.2.2.1 10.2.2.2

S0S1

RouterA#sh cdp ? entry Information for specific neighbor entry interface CDP interface status and configuration neighbors CDP neighbor entries traffic CDP statistics <cr>RouterA(config)#no cdp run RouterA(config)#interface serial0 RouterA(config-if)#no cdp enable


SwitchA also provides its Mac address

Using the show cdp neighbor Command

Using the show cdp neighbor Command

RouterA#sh cdp neighborsCapability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge S - Switch, H - Host, I - IGMP, r - Repeater

Device ID Local Intrfce Holdtme Capability Platform Port IDRouterB Ser 0 148 R 2522 Ser 1SwitchA0050BD855780 Eth 0 167 T S 1900 2


10.3.3.2 10.3.3.1 10.1.1.110.1.1.2

10.2.2.1 10.2.2.2

S0S1


Using the show cdp entry Command

Using the show cdp entry Command

RouterA#sh cdp entry *-------------------------Device ID: RouterB Entry address(es): IP address: 10.1.1.2 Platform: cisco 2522, Capabilities: Router Interface: Serial0, Port ID (outgoing port): Serial1Holdtime : 168 sec

Version :Cisco Internetwork Operating System Software IOS (tm) 2500 Software (C2500-JS-L), Version 12.0(3), RELEASE SOFTWARE (fci)Copyright (c) 1986-1999 by cisco Systems, Inc.Compiled Mon 08-Feb-99 18:18 by phanguye


10.3.3.2 10.3.3.1 10.1.1.110.1.1.2

10.2.2.1 10.2.2.2

S0S1


Additional CDP CommandsAdditional CDP Commands

RouterA#sh cdp trafficCDP counters :

Packets output: 56, Input: 38Hdr syntax: 0, Chksum error: 0, Encaps failed: 3No memory: 0, Invalid packet: 0, Fragmented: 0

RouterA#sh cdp interface BRI0 is administratively down, line protocol is down Encapsulation HDLC Sending CDP packets every 60 seconds Holdtime is 180 seconds


10.3.3.2 10.3.3.1 10.1.1.110.1.1.2

10.2.2.1 10.2.2.2

S0S1


Using Telnet to Connect to Remote Devices

Using Telnet to Connect to Remote Devices

Remote device


10.3.3.2 10.3.3.1 10.1.1.110.1.1.2

10.2.2.1 10.2.2.2

S0S1

RouterA#telnet 10.2.2.2 Trying 10.2.2.2 ... Open-------------------------------------------------Catalyst 1900 Management ConsoleCopyright (c) Cisco Systems, Inc. 1993-1998All rights reserved.Enterprise Edition SoftwareEthernet Address: 00-90-86-73-33-40PCA Number: 73-2239-06PCA Serial Number: FAA02359H8KModel Number: WS-C1924-ENSystem Serial Number: FAA0237X0FQ..SwitchB>


Viewing Telnet ConnectionsViewing Telnet Connections


10.3.3.2 10.3.3.1 10.1.1.110.1.1.2

10.2.2.1 10.2.2.2

S0S1

RouterA#sh sessionConn Host Address Byte Idle Conn Name 1 10.1.1.2 10.1.1.2 0 1 10.1.1.2* 2 10.3.3.2 10.3.3.2 0 0 10.3.3.2

RouterA#sh user Line User Host(s) Idle Location* 0 con 0 10.1.1.2 3 10.3.3.2 2 11 vty 0 idle 1 10.1.1.2


Suspending a Telnet SessionSuspending a Telnet Session


10.3.3.2 10.3.3.1 10.1.1.110.1.1.2

10.2.2.1 10.2.2.2

S0S1

RouterB#<Ctrl-Shift-6>xRouterA#sh sessionConn Host Address Byte Idle Conn Name 1 10.1.1.2 10.1.1.2 0 1 10.1.1.2RouterA#resume 1RouterB#


RouterA#disconnect Closing connection to 10.3.3.2 [confirm]

RouterA#clear line 11[confirm] [OK]

Closing a Telnet SessionClosing a Telnet Session

Closing a session opened by a remote device

Closing the current session opened by you


10.3.3.2 10.3.3.1 10.1.1.110.1.1.2

10.2.2.1 10.2.2.2

S0S1


Using the ping and trace Commands

Using the ping and trace Commands

Test connectivity and path to a remote device

Router##ping 10.1.1.10

Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 10.1.1.10, timeout is 2 seconds:!!!!!Success rate is 100 percent (5/5), round-trip min/avg/max = 4/4/4 ms

Router#trace 10.1.1.10

Type escape sequence to abort.Tracing the route to 10.1.1.10

1 10.1.1.10 4 msec 4 msec 4 msecRouter#


Router Power on/Bootup Sequence

Router Power on/Bootup Sequence

• Power on self test (POST)

• Load and run bootstrap code

• Find the IOS software

• Load the IOS software

• Find the configuration

• Load the configuration

• Run


Router Internal ComponentsRouter Internal Components

RAM Config register

ROM

Flash

NVRAM

Interfaces


ROM FunctionsROM Functions

ROM

Contains microcode for basic functions

Bootstrap

Mini IOSROM

monitor

POST

show version

Console


Finding the IOSFinding the IOS

Flash

showversion

show startup-config

IOSOrder of search:

1. Check configuration register

2. Parse config in NVRAM

3. Default to first file in Flash

4. Attempt net boot

5. RXBOOT

6. ROMMON

Console

Config register

NVRAM


Router Start-up Flow ChartRouter Start-up Flow Chart

Use IOS fromFlash

Attempt to getIOS from network

Use IOS in ROM(RXBoot mode)

Check start-upconfig

Boot field =0

0x0

Boot field =1

0x1

Boot system

commands?

Config regbit 13=1

?

5 failures?

Valid IOS inFlash

?

Do whatthey say

RunROM

Monitor

START

Yes

Yes

No

No

Yes

No

No

Yes

Yes

No

NoYes Success

?

No

Yes

Use file fromNetwork

Load IOSValid config

?

Config regbit 6=1

?

Yes

No Yes

SETUPDIALOG

NORMAL START UP

COMPLETE

No


Determining the Current Configuration Register Value

Determining the Current Configuration Register Value

wg_ro_a#show versionCisco Internetwork Operating System Software IOS (tm) 2500 Software (C2500-JS-L), Version 12.0(3), RELEASE SOFTWARE (fc1)Copyright (c) 1986-1999 by cisco Systems, Inc.Compiled Mon 08-Feb-99 18:18 by phanguyeImage text-base: 0x03050C84, data-base: 0x00001000

ROM: System Bootstrap, Version 11.0(10c), SOFTWAREBOOTFLASH: 3000 Bootstrap Software (IGS-BOOT-R), Version 11.0(10c), RELEASE SOFTWARE (fc1)

wg_ro_a uptime is 20 minutesSystem restarted by reloadSystem image file is "flash:c2500-js-l_120-3.bin"

--More--

Configuration register is 0x2102

Configuration register value in show version


Configuration Register ValuesConfiguration Register Values

• Configuration register bits 3, 2, 1, and 0 set boot option

Router#configure terminalRouter(config)#config-register 0x2102[Ctrl-Z]Router#reload




Configuration Register Boot Field Value

0x0

Meaning

Use ROM monitor mode(Manually boot using the b command)






0x0

0x1

Meaning


Automatically boot from ROM(Provides IOS subset)




• Check configuration register value with show version



0x0

0x2 to 0xF

0x1

Meaning


Examine NVRAM for boot system commands (0x2 default if router has Flash)

Automatically boot from ROM(Provides IOS subset)



Loading the IOS from FlashLoading the IOS from Flash

Flash

IOS

IOSshow flash

Flash file is decompressed into RAM

Console

RAM


show flash Commandshow flash Command

wg_ro_a#sh flash

System flash directory:File Length Name/status 1 10084696 c2500-js-l_120-3.bin [10084760 bytes used, 6692456 available, 16777216 total]16384K bytes of processor board System flash (Read ONLY)

wg_ro_a#sh flash

System flash directory:File Length Name/status 1 10084696 c2500-js-l_120-3.bin [10084760 bytes used, 6692456 available, 16777216 total]16384K bytes of processor board System flash (Read ONLY)


Loading the ConfigurationLoading the Configuration

Console

IOS

Setup utility

showstartup-config

showrunning-config

• Load and execute config from NVRAM

• If no config in NVRAM, enter setup mode

ConfigConfig

RAM NVRAM


show running and show startup Commands

show running and show startup Commands

wg_ro_c#show startup-configUsing 1359 out of 32762 bytes!version 12.0!

-- More --

wg_ro_c#show running-configBuilding configuration...

Current configuration:!version 12.0!

-- More --

In NVRAMIn RAM

Display current and saved configuration


Sources of ConfigurationsSources of Configurations

ConfigConfig

RAM NVRAM

• NVRAM

copy running startup

copy startup running (merge)



ConfigConfig

RAM NVRAM

• NVRAM

• Terminal



config term

(merge)



ConfigConfig

Console

RAM NVRAM

• NVRAM

• Terminal

• TFTP server



TFTPserver

copy start tftp

copy tftp start

copy run tftp

copy tftp run

(merge)

config term

(merge)



ConfigConfig

Console

RAM NVRAM

• NVRAM

• Terminal

• TFTP server

• Erase Start



TFTPserver

Blank000000000000

erasestart

config term

(merge)

copy tftp run

(merge) copy tftp start

copy start tftpcopy run tftp


copy run tftp and copy tftp run Commands

copy run tftp and copy tftp run Commands

wg_ro_a#copy running-config tftp Address or name of remote host []? 10.1.1.1 Destination filename [running-config]? wgroa.cfg .!!1684 bytes copied in 13.300 secs (129 bytes/sec) wg_ro_a#copy tftp running-config Address or name of remote host []? 10.1.1.1 Source filename []? wgroa.cfg Destination filename [running-config]? Accessing tftp://10.1.1.1/wgroa.cfg... Loading wgroa.cfg from 10.1.1.1 (via Ethernet0): ![OK - 1684/3072 bytes]

1684 bytes copied in 17.692 secs (99 bytes/sec)

wg_ro_a#copy running-config tftp Address or name of remote host []? 10.1.1.1 Destination filename [running-config]? wgroa.cfg .!!1684 bytes copied in 13.300 secs (129 bytes/sec) wg_ro_a#copy tftp running-config Address or name of remote host []? 10.1.1.1 Source filename []? wgroa.cfg Destination filename [running-config]? Accessing tftp://10.1.1.1/wgroa.cfg... Loading wgroa.cfg from 10.1.1.1 (via Ethernet0): ![OK - 1684/3072 bytes]

1684 bytes copied in 17.692 secs (99 bytes/sec)


Cisco IOS File Systems and Devices

Cisco IOS File Systems and Devices

RAM NVRAM

TFTPserver

Flash

flash:

system: nvram:

tftp:


Managing IOS ImagesManaging IOS Images

Networkserver

FLASHFLASH

Router

c2500-js-l_120-3.bin

Networkserver


Preparing for a Network Backup Image


• Check access to the server

RouterNetworkserver




•Check access to the server•Check space available on the server

RouterNetworkserver




• Check access to the server• Check space available on the server• Check file naming convention

Router

c2500-js-l_120-3.bin

Networkserver




Router

c2500-js-l_120-3.bin

Networkserver

• Check access to the server• Check space available on the server• Check file naming convention• Create file on server if required


wg_ro_a#show flash

System flash directory:File Length Name/status 1 10084696 c2500-js-l_120-3.bin

[10084760 bytes used, 6692456 available, 16777216 total]16384K bytes of processor board System flash (Read ONLY)

Verifying Memory and Deciphering Image Filenames

Verifying Memory and Deciphering Image Filenames

Verify Flash memory has room for the IOS image


wg_ro_a#copy flash tftpSource filename []? c2500-js-l_120-3.binAddress or name of remote host []? 10.1.1.1Destination filename [c2500-js-l_120-3.bin]? !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!<output omitted>10084696 bytes copied in 709.228 secs (14223 bytes/sec)wg_ro_a#

Creating a Software Image Backup

Creating a Software Image Backup

Back up current files prior to updating Flash

Networkserver

FLASHFLASH

copy flash tftp


wg_ro_a#copy tftp flashAddress or name of remote host [10.1.1.1]? Source filename []? c2500-js-l_120-3.binDestination filename [c2500-js-l_120-3.bin]? Accessing tftp://10.1.1.1/c2500-js-l_120-3.bin...Erase flash: before copying? [confirm]Erasing the flash filesystem will remove all files! Continue? [confirm]Erasing device... eeeee (output omitted) ...erasedErase of flash: completeLoading c2500-js-l_120-3.bin from 10.1.1.1 (via Ethernet0): !!!!!!!!!!!!!!!!!!!!(output omitted)[OK - 10084696/20168704 bytes]Verifying checksum... OK (0x9AA0)10084696 bytes copied in 309.108 secs (32636 bytes/sec)wg_ro_a#

Upgrading the Image from the Net

Upgrading the Image from the Net

• Erase Flash occurs before loading new image• Note message that image already exists

Networkserver

FLASHFLASH


Visual ObjectiveVisual Objective

core_ server10.1.1.1

255.255.255.0

wg_sw_a10.1.1.10

255.255.255.0

wg_sw_l10.1.1.120

255.255.255.0

wg_pc_a

wg_pc_l

...

console

10.1.1.121 255.255.255.0

e0/2fa0/26(port A)

e0/2

e0

e0fa0/26(port A)

fa0/1 fa0/12

fa0/24

core_sw_a10.1.1.2

255.255.255.0

10.1.1.11255.255.255.0

wg_ro_l

A/B

A/B

wg_ro_a

console

consoleconsole

pod sw ro’s e0A 10.1.1.10 10.1.1.11B 10.1.1.20 10.1.1.21 C 10.1.1.30 10.1.1.31D 10.1.1.40 10.1.1.41E 10.1.1.50 10.1.1.51F 10.1.1.60 10.1.1.61G 10.1.1.70 10.1.1.71H 10.1.1.80 10.1.1.81I 10.1.1.90 10.1.1.91J 10.1.1.100 10.1.1.101K 10.1.1.110 10.1.1.111L 10.1.1.120 10.1.1.121


After completing this chapter, you should be able to perform the following tasks:

• Use Cisco Discovery Protocol from a device to get information about neighboring devices

• Use Telnet to retrieve information about remote devices

• Determine the load location of the IOS image

• List the commands to load an IOS image file

SummarySummary


Review QuestionsReview Questions

1. What CDP command is used to get information about one specific neighbor?

2. What key combination suspends a Telnet session?

3. From which three locations can an active configuration file originate?

4.What show command lists the value of the Configuration Register?

© 1999, cisco systems, inc. 5-1 chapter 5 managing your network environment

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