managing your network environment

Objectives Upon completion of this chapter, you will be able to perform the following tasks: Gather information about neighboring devices. Gather information about remote devices. Create a simple network diagram to document the network. Determine the location from which a configuration and Cisco IOS image will be loaded.

Cisco Discovery Protocol CDP is a proprietary utility that gives you a summary of directly connected switches, routers, and other Cisco devices. CDP discovers neighboring devices regardless of which protocol suite they are running. Physical media must support the Subnetwork Access Protocol (SNAP) encapsulation. Upper-Layer Entry Addresses Cisco Proprietary Data-Link Protocol Media Supporting SNAP TCP/IP Novell IPX CDP discovers and displays information about directly connected Cisco devices. ATM Others LANs Frame Relay AppleTalk Others

CDP runs on routers with Cisco IOS ® software Release 10.3 or later and Cisco switches and hubs software. Summary information includes: Device identifiers. Address list. Port identifier. Capabilities list. Platform . Discovering Neighbors with CDP CDP CDP CDP show cdp

Using CDP SwitchB RouterA RouterB SwitchA 10.3.3.2 10.3.3.1 10.1.1.1 10.1.1.2 10.2.2.1 10.2.2.2 S0 S1 RouterA#sh cdp ? entry Information for specific neighbor entry interface CDP interface status and configuration neighbors CDP neighbors entries traffic CDP statistics <cr> RouterA(config)#no cdp run RouterA(config)#interface serial0 RouterA(config-if)#no cdp enable

Using the show cdp neighbor Command SwitchA also provides its MAC address RouterA#sh cdp neighbors Capability 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 ID RouterB Ser 0 148 R 2522 Ser 1 SwitchA0050BD855780 Eth 0 167 T S 1900 2 SwitchB RouterA RouterB SwitchA 10.3.3.2 10.3.3.1 10.1.1.1 10.1.1.2 10.2.2.1 10.2.2.2 S0 S1

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): Serial1 Holdtime : 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 SwitchB RouterA RouterB SwitchA 10.3.3.2 10.3.3.1 10.1.1.1 10.1.1.2 10.2.2.1 10.2.2.2 S0 S1

Additional CDP Commands RouterA#sh cdp traffic CDP counters : Packets output: 56, Input: 38 Hdr syntax: 0, Chksum error: 0, Encaps failed: 3 No 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 SwitchB RouterA RouterB SwitchA 10.3.3.2 10.3.3.1 10.1.1.1 10.1.1.2 10.2.2.1 10.2.2.2 S0 S1

Using Telnet to Connect to Remote Devices Remote device SwitchB RouterA RouterB SwitchA 10.3.3.2 10.3.3.1 10.1.1.1 10.1.1.2 10.2.2.1 10.2.2.2 S0 S1 RouterA#telnet 10.2.2.2 Trying 10.2.2.2 ... Open ------------------------------------------------- Catalyst 1900 Management Console Copyright (c) Cisco Systems, Inc. 1993-1998 All rights reserved. Enterprise Edition Software Ethernet Address: 00-90-86-73-33-40 PCA Number: 73-2239-06 PCA Serial Number: FAA02359H8K Model Number: WS-C1924-EN System Serial Number: FAA0237X0FQ . . SwitchB>

Viewing Telnet Connections SwitchB RouterA RouterB SwitchA 10.3.3.2 10.3.3.1 10.1.1.1 10.1.1.2 10.2.2.1 10.2.2.2 S0 S1 RouterA#sh session Conn 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 Session SwitchB RouterA RouterB SwitchA 10.3.3.2 10.3.3.1 10.1.1.1 10.1.1.2 10.2.2.1 10.2.2.2 S0 S1 RouterB#<Ctrl-Shift-6>x RouterA#sh session Conn Host Address Byte Idle Conn Name 1 10.1.1.2 10.1.1.2 0 1 10.1.1.2 RouterA#resume 1 RouterB#

Closing a Telnet Session RouterA#disconnect Closing connection to 10.3.3.2 [confirm] RouterA#clear line 11 [confirm] [OK] Closes a session opened by a remote device Closes the current session opened by you SwitchB RouterA RouterB SwitchA 10.3.3.2 10.3.3.1 10.1.1.1 10.1.1.2 10.2.2.1 10.2.2.2 S0 S1

Using the ping and trace Commands Tests the 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 msec Router#

Router Power On/Bootup Sequence Perform power-on self test (POST). Load and run bootstrap code. Find the Cisco IOS software. Load the Cisco IOS software. Find the configuration. Load the configuration. Run the configured Cisco IOS software.

Router Internal Components RAM Configuration Register ROM Flash NVRAM Interfaces

ROM Functions ROM Contains microcode for basic functions Bootstrap Mini IOS software file ROM Monitor POST show version Console

Finding the Cisco IOS Flash show version show startup-config Cisco IOS Software Order of search: 1. Checks configuration register 2. Parses config in NVRAM 3. Defaults to first file in Flash 4. Attempts to boot from network server 5. RXBOOT 6. ROMMON Console Configuration Register NVRAM

Router Startup Flowchart Use IOS from Flash Attempt to Get IOS from Network Use IOS in ROM (rxboot Mode) Check Startup Config Boot Field = 0 0x0 Boot Field = 1 0x1 Boot System Commands ? Config reg bit 13 = 1 ? 5 Failures ? Valid IOS in Flash ? Do What They Say Run ROM Monitor START Yes Yes No No Yes No No Yes Yes No No Yes Success ? No Yes Use File from Network Load IOS Valid Config ? Config Reg Bit 6 = 1 ? Yes No Yes SETUP DIALOG NORMAL STARTUP COMPLETE No

Determining the Current Configuration Register Value wg_ro_a# show version Cisco 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 phanguye Image text-base: 0x03050C84, data-base: 0x00001000 ROM: System Bootstrap, Version 11.0(10c), SOFTWARE BOOTFLASH: 3000 Bootstrap Software (IGS-BOOT-R), Version 11.0(10c), RELEASE SOFTWARE (fc1) wg_ro_a uptime is 20 minutes System restarted by reload System image file is "flash:c2500-js-l_120-3.bin" --More-- Configuration register is 0x2102 Configuration register value in show version

Configuration Register Values Configuration register bits 3, 2, 1, and 0 set boot option Router#configure terminal Router(config)# config-register 0x2102 [Ctrl-Z] Router#reload

Configuration Register Values Configuration register bits 3, 2, 1, and 0 set boot option Configuration Register Boot Field Value 0x0 Meaning Use ROM monitor mode (Manually boot using the b command) Router#configure terminal Router(config)# config-register 0x2102 [Ctrl-Z] Router#reload

Configuration Register Values Configuration register bits 3, 2, 1, and 0 set boot option Configuration Register Boot Field Value 0x0 0x1 Meaning Use ROM monitor mode (Manually boot using the b command) Automatically boot from ROM (Provides IOS subset) Router#configure terminal Router(config)# config-register 0x2102 [Ctrl-Z] Router#reload

Configuration register bits 3, 2, 1, and 0 set boot option. Check configuration register value with show version. Configuration Register Values Configuration Register Boot Field Value 0x0 0x2 to 0xF 0x1 Meaning Use ROM monitor mode (manually boot using the b command). Examine NVRAM for boot system commands (0x2 default if router has Flash). Automatically boot from ROM (provides Cisco IOS software subset). Router#configure terminal Router(config)# config-register 0x2102 [Ctrl-Z] Router#reload

Loading the Cisco IOS from Flash Flash Cisco IOS Cisco IOS show flash Flash file is decompressed into RAM. Console RAM

show 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)

Loading the Configuration Console Cisco IOS Setup Utility show startup-config show running-config Load and execute the configuration from NVRAM. If no configuration is present in NVRAM, enter setup mode. Config Config RAM NVRAM

show running and show startup Commands wg_ro_c# show startup-config Using 1359 out of 32762 bytes ! version 12.0 ! -- More -- wg_ro_c # show running-config Building configuration... Current configuration: ! version 12.0 ! -- More -- In NVRAM In RAM Displays current and saved configuration

Sources of Configurations Config Config RAM NVRAM NVRAM copy running startup copy startup running ( merge )

Sources of Configurations Config Config RAM NVRAM NVRAM Terminal copy running startup copy startup running ( merge ) config term ( merge )

Sources of Configurations Config Config Console RAM NVRAM NVRAM Terminal TFTP server copy running startup copy startup running ( merge ) TFTP server copy start tftp copy tftp start copy run tftp copy tftp run ( merge ) config term ( merge)

Sources of Configurations Configuration Configuration Console RAM NVRAM NVRAM Terminal TFTP server Erase start copy running startup copy startup running ( merge ) TFTP Server Blank 000000 000000 erase start config term ( merge ) copy tftp run ( merge ) copy tftp start copy start tftp copy run tftp

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)

Cisco IOS File Systems and Devices RAM NVRAM TFTP Server Flash flash: system: nvram: tftp:

Managing Cisco IOS Images Network Server FLASH Router Network Server c2500-js-l_120-3.bin

Preparing for a Network Backup Image Check access to the server Router Network Server

Preparing for a Network Backup Image Check access to the server Check space available on the server Router Network Server

Preparing for a Network Backup Image Check access to the server Check space available on the server Check file naming convention Router Network Server c2500-js-l_120-3.bin

Preparing for a Network Backup Image Router Network Server Check access to the server. Check space available on the server. Check the filename convention. Create the file on the server, if required. c2500-js-l_120-3.bin

Verifying Memory and Deciphering Image Filenames Verify that Flash memory has room for the Cisco IOS image. 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)

Creating a Software Image Backup Back up current files prior to updating Flash. Network Server FLASH copy flash tftp wg_ro_a# copy flash tftp Source filename []? c2500-js-l_120-3.bin Address or name of remote host []? 10.1.1.1 Destination filename [c2500-js-l_120-3.bin]? !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! <output omitted> 10084696 bytes copied in 709.228 secs (14223 bytes/sec) wg_ro_a#

Upgrading the Image from the Network Erase Flash occurs before loading new image. Note the message that the image already exists. Network Server FLASH wg_ro_a# copy tftp flash Address or name of remote host [10.1.1.1]? Source filename []? c2500-js-l_120-3.bin Destination 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) ...erased Erase of flash: complete Loading 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#

Visual Objective Pod Switch Router e0 A 10.1.1.10 10.1.1.11 B 10.1.1.20 10.1.1.21 C 10.1.1.30 10.1.1.31 D 10.1.1.40 10.1.1.41 E 10.1.1.50 10.1.1.51 F 10.1.1.60 10.1.1.61 G 10.1.1.70 10.1.1.71 H 10.1.1.80 10.1.1.81 I 10.1.1.90 10.1.1.91 J 10.1.1.100 10.1.1.101 K 10.1.1.110 10.1.1.111 L 10.1.1.120 10.1.1.121 core_ server 10.1.1.1 255.255.255.0 wg_sw_a 10.1.1.10 255.255.255.0 wg_sw_l 10.1.1.120 255.255.255.0 wg_pc_a wg_pc_l ... Console 10.1.1.121 255.255.255.0 e0/2 fa0/26 (port A) e0/2 e0 e0 fa0/26 (port A) fa0/1 fa0/12 fa0/24 core_sw_a 10.1.1.2 255.255.255.0 10.1.1.11 255.255.255.0 wg_ro_l A/B A/B wg_ro_a Console Console Console core_ro fa0/23 fa0/0

After completing this chapter, you should be able to perform the following tasks: Use the 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 Cisco IOS image. List the commands to load a Cisco IOS image file. Summary

Review 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?

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