Flash,ios,ram,cdp

Chapter 5

Managing Your  Network Environment © 1999, Cisco Systems, Inc. 

5­1

Objectives 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 © 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­2

Cisco Discovery  Protocol   Upper­Layer  Entry Addresses

TCP/IP

Cisco Proprietary Data­Link Protocol

CDP discovers and shows information about  directly connected Cisco devices

Media Supporting  SNAP

LANs

Novell  IPX

Frame Relay

AppleTalk

ATM

Others

Others

• 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 © 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­3

Discovering Neighbors  with CDP Runs on routers with Cisco IOS  10.3 or later and Cisco switches  and hubs Summary information  includes: • Device identifiers • Address list

CDP

CDP

CDP

• Port identifier

show cdp

• Capabilities list • Platform  © 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­4

Using CDP SwitchA

RouterA

S1

S0 10.3.3.2

10.3.3.1

10.1.1.1

10.1.1.2

RouterB 10.2.2.1

SwitchB 10.2.2.2

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

© 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­5

Using the show cdp neighbor  Command SwitchA

RouterA

S1

S0 10.3.3.2

10.3.3.1

10.1.1.1

10.1.1.2

RouterB

SwitchB

10.2.2.1

10.2.2.2

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 RouterB Ser 0 SwitchA0050BD855780 Eth 0

Holdtme 148 167

Capability R T S

Platform 2522 1900

Port ID Ser 1 2

SwitchA also provides its Mac address © 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­6

Using the show cdp entry  Command SwitchA

RouterA

S1

S0 10.3.3.2

10.3.3.1

10.1.1.1

10.1.1.2

RouterB 10.2.2.1

SwitchB 10.2.2.2

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 © 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­7

Additional CDP Commands SwitchA

RouterA

S1

S0 10.3.3.2

10.3.3.1

10.1.1.1

10.1.1.2

RouterB 10.2.2.1

SwitchB 10.2.2.2

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 © 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­8

Using Telnet to Connect to  Remote Devices SwitchA

RouterA

S1

S0 10.3.3.2

10.3.3.1

10.1.1.1

10.1.1.2

RouterB 10.2.2.1

SwitchB 10.2.2.2

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 Remote device Model Number: WS-C1924-EN System Serial Number: FAA0237X0FQ . . SwitchB> © 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­9

Viewing Telnet Connections SwitchA

RouterA

S1

S0 10.3.3.2

10.3.3.1

RouterA#sh session Conn Host 1 10.1.1.2 * 2 10.3.3.2

RouterA#sh user Line User * 0 con 0 11 vty 0

© 1999, Cisco Systems, Inc. 

10.1.1.1

RouterB

10.1.1.2

Address 10.1.1.2 10.3.3.2

Host(s) 10.1.1.2 10.3.3.2 idle

10.2.2.1

Byte 0 0

SwitchB 10.2.2.2

Idle Conn Name 1 10.1.1.2 0 10.3.3.2

Idle Location 3 2 1 10.1.1.2

www.cisco.com

ICND—5­10

Suspending a Telnet Session SwitchA

RouterA

S1

S0 10.3.3.2

10.3.3.1

RouterB#x RouterA#sh session Conn Host 1 10.1.1.2 RouterA#resume 1 RouterB#

© 1999, Cisco Systems, Inc. 

10.1.1.1

10.1.1.2

Address 10.1.1.2

www.cisco.com

RouterB 10.2.2.1

Byte 0

SwitchB 10.2.2.2

Idle Conn Name 1 10.1.1.2

ICND—5­11

Closing a Telnet Session SwitchA

RouterA

S1

S0 10.3.3.2

10.3.3.1

10.1.1.1

10.1.1.2

RouterB 10.2.2.1

SwitchB 10.2.2.2

Closing the current  RouterA#disconnect Closing connection to 10.3.3.2 [confirm] session opened by you

Closing a session opened  by a remote device

RouterA#clear line 11 [confirm] [OK]

© 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­12

Using the ping and trace  Commands 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#

 Test connectivity and path to a remote device © 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­13

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

© 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­14

Router Internal Components NVRAM Config register

RAM

ROM Interfaces Flash

© 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­15

ROM Functions ROM

Bootstrap

POST show version

Mini IOS

ROM monitor

Console

Contains microcode for basic functions © 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­16

Finding the IOS show  startup­config

NVRAM Config register

Flash IOS

© 1999, Cisco Systems, Inc. 

Console

show version

Order 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 www.cisco.com

ICND—5­17

Router Start­up Flow Chart Boot  field =1 0x1

START

Boot  system Yes commands ?

Check  start­up config

No

Yes

Boot  field =0 0x0

No

No No Yes

Run ROM  Monitor

Yes

Use IOS from Flash

Attempt to get IOS from  network

5 failures ?

No Use IOS in ROM (RXBoot mode)

Load IOS

Yes

Config reg bit 13=1 ? 

Config reg bit 6=1 ?

No

Success ?

No

Yes

© 1999, Cisco Systems, Inc. 

Valid  IOS in Flash ?

No

Yes

Do what they say

www.cisco.com

Yes

Valid  config ?

No

Use file from Network

 NORMAL  START UP COMPLETE

Yes

  SETUP DIALOG

ICND—5­18

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 © 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­19

Configuration Register Values Router#configure terminal Router(config)#config-register 0x2102 [Ctrl-Z] Router#reload

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

© 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­20

Configuration Register Values Router#configure terminal Router(config)#config-register 0x2102 [Ctrl-Z] Router#reload

• Configuration register bits 3, 2, 1, and 0 set boot option Configuration Register  Boot Field Value 0x0

© 1999, Cisco Systems, Inc. 

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

www.cisco.com

ICND—5­21

Configuration Register Values Router#configure terminal Router(config)#config-register 0x2102 [Ctrl-Z] Router#reload

• Configuration register bits 3, 2, 1, and 0 set boot option Configuration Register  Boot Field Value

© 1999, Cisco Systems, Inc. 

Meaning

0x0

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

0x1

Automatically boot from ROM (Provides IOS subset)

www.cisco.com

ICND—5­22

Configuration Register Values Router#configure terminal Router(config)#config-register 0x2102 [Ctrl-Z] Router#reload

• Configuration register bits 3, 2, 1, and 0 set boot option Configuration Register  Boot Field Value

Meaning

0x0

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

0x1

Automatically boot from ROM (Provides IOS subset)

0x2 to 0xF

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

• Check configuration register value with show version © 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­23

Loading the IOS from Flash RAM IOS

Flash IOS

Console show flash

Flash file is decompressed into RAM © 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­24

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)

© 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­25

Loading the Configuration RAM

NVRAM

Config

Config

IOS

show running­config

show startup­config Console Setup utility

• Load and execute config from NVRAM • If no config in NVRAM, enter setup mode © 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­26

show running and show  startup Commands In RAM

In NVRAM

wg_ro_c#show running-config Building configuration...

wg_ro_c#show startup-config Using 1359 out of 32762 bytes ! version 12.0 ! -- More --

Current configuration: ! version 12.0 ! -- More --

Display current and saved configuration

© 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­27

Sources of Configurations RAM Config

copy running startup copy startup running (merge)

NVRAM Config

• NVRAM

© 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­28

Sources of Configurations RAM Config

copy running startup copy startup running (merge)

NVRAM Config

config term (merge)

• NVRAM • Terminal

© 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­29

Sources of Configurations RAM

copy running startup

Config

copy startup running (merge)

NVRAM Config

config term (merge) copy tftp run  Console (merge)

• NVRAM

copy run tftp

• Terminal • TFTP server © 1999, Cisco Systems, Inc. 

copy tftp start copy start tftp

TFTP server

www.cisco.com

ICND—5­30

Sources of Configurations RAM

copy running startup

Config

copy startup running (merge)

NVRAM Config

config term (merge) copy tftp run  Console (merge)

• NVRAM

copy run tftp

• Terminal • TFTP server

copy tftp start copy start tftp

TFTP server

erase start Blank 000000 000000

• Erase Start © 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­31

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)

© 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­32

Cisco IOS File Systems and  Devices

RAM

NVRAM

system:

nvram:

TFTP server

Flash

tftp:

flash: © 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­33

Managing IOS Images c2500­js­l_120­3.bin

Network server

Router

FLASH

© 1999, Cisco Systems, Inc. 

Network server

www.cisco.com

ICND—5­34

Preparing for a Network  Backup Image

Network server

Router

• Check access to the server

© 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­35

Preparing for a Network  Backup Image

Network server

Router

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

© 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­36

Preparing for a Network  Backup Image c2500­js­l_120­3.bin

Network server

Router

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

© 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­37

Preparing for a Network  Backup Image c2500­js­l_120­3.bin

Network server

Router

• Check access to the server • Check space available on the server • Check file naming convention • Create file on server if required © 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­38

Verifying Memory and  Deciphering Image Filenames 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)

Verify Flash memory has room for the IOS image

© 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­39

Creating a Software Image  Backup FLASH

copy flash tftp

Network server

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]? !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

10084696 bytes copied in 709.228 secs (14223 bytes/sec) wg_ro_a#

Back up current files prior to updating Flash © 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­40

Upgrading the Image from the  Net FLASH

Network server

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#

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

© 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­41

Visual Objective wg_pc_a

pod A B C D E F G H I J K L

sw  10.1.1.10 10.1.1.20 10.1.1.30 10.1.1.40 10.1.1.50 10.1.1.60 10.1.1.70 10.1.1.80 10.1.1.90 10.1.1.100 10.1.1.110 10.1.1.120

ro’s e0 10.1.1.11 10.1.1.21  10.1.1.31 10.1.1.41 10.1.1.51 10.1.1.61 10.1.1.71 10.1.1.81 10.1.1.91 10.1.1.101 10.1.1.111 10.1.1.121

console fa0/26 (port A)

core_ server 10.1.1.1 255.255.255.0 © 1999, Cisco Systems, Inc. 

e0/2

console fa0/26 (port A)

...

console

e0

wg_ro_a

10.1.1.11 255.255.255.0 wg_pc_l

wg_sw_a 10.1.1.10  255.255.255.0

fa0/1 fa0/24

A/B

A/B e0/2

wg_sw_l 10.1.1.120 255.255.255.0

e0 10.1.1.121  255.255.255.0

console wg_ro_l

fa0/12

  

core_sw_a 10.1.1.2 255.255.255.0 www.cisco.com

ICND—5­42

Summary 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 © 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­43

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? © 1999, Cisco Systems, Inc. 

www.cisco.com

ICND—5­44