This document provides instructions and commands for booting, backing up, restoring, and upgrading Cisco IOS, managing the Cisco file system, backing up and restoring the router configuration, using Cisco Discovery Protocol to gather neighbor and interface information, using Telnet to connect to remote devices, troubleshooting network connectivity issues, and using debugging commands. It also discusses using host tables or DNS to resolve hostnames when connecting to devices.

1. Boot System Commands
Configure router to boot another IOS
All routers can boot from TFTP Server
router(config)#boot ?
router(config)#boot system ?
router(config)#boot system flash <iosname>.bin
router(config)#boot system tftp <iosname>bin <ip>
router(config)#boot system rom
router(config)#do show run | include boot system

2. Backing Up and Restoring
Cisco IOS
Make sure you access network server
Ensure that the network server has adequate space for
the code image
Verify the file naming and path requirements
Besides:
TFTP Server software is running
Ethernet connection between workstation and router is
crossover
Workstation and Router interface are on the same subnet

3. Verify Flash Memory and
Back IOS
Router#show flash
Router#show version
Router#ping <tftp­server­ip>
Router#copy flash tftp
Walk through questions!

4. Restore / Upgrade IOS
Router#copy tftp flash

5. Cisco File System
Router#pwd
Router#dir
Router#delete flash:<filename>
Router#sh flash
Router#copy tftp://<ip>//file name/ flash:/
Router#show file information flash:<filename>

6. Backup Configuration
Verify Stored Configuration
Router#show startup­config
Verify Current Configuration
Router#show running­config
Coppying Current Configuration
Copy running­config startup­config
And vice versa!

7. Copy running-config to TFTP
Router#copy running­config tftp

8. Restoring running-config
Router#copy tftp running­config

9. Erasing the Configuration
Router#erasse startup­config
Router#reload
Remember: When you are prompted witht he message,
answer: n
What happens if you answer yes?

10. Cisco File System
Router#show file informationnvram:running­config
R#cd nvram
R#pwd
R#cd system:
R#dir
R#config net
R#copy tftp://<ip>/<file> system://running­config

11. Cisco CDP
Cisco Discovery Protocol
Show CDP Gives information
CDP Timer: how often CDP packets are transmitted
CDP holdtime: amount of time that device will hold
packets received from neighbor devices
R#show cdp
R(config)#cdp ?

12. Gathering Neighbor Info
R#sho cdp neighbors
R#sho cdp neighbors detail
R#sh cdp nei de
R#sh cdp entry *
Same as the previous... but?
R#show cdp entry * ?
Protocols
Version

13. Gathering Interface Traffic
R#sh cdp traffic
Shows how many CDP packets have been sent and
received

14. Gathering Port and
Interface Information
R#sh cdp interface
Gives status on router interfaces or switch ports
To turn off cdp on router:
R(config)#no cdp run
Enable CDP
R(confi)#cdp enable

15. Telnet
Posted Online
http://blog.helghareeb.net/2012/01/03/telnet­lab/
R#sh sessions
See sessions from your router to a remote device
R#sh users
List all active consoles and VTY pots on my router
Exit: Close telnet session
R#disconnect ?
Close connection to router

16. Resolving Hostname
Use hostname rather IP address to connect to Remote
Device
Translate hostname to IP
Two ways:
Build host table on each router
Build DNS Server (dynamic host table)

17. Build Host Table
Ip host <host­name> [tcp­port#] <ip­address>
Default Telnet Port is 23
R(config)#ip host R1 <ip>
R(config)#do show hosts
R#R1
Trying to connect to my telnet... WoW!

18. Using DNS to Resolve
Names
Use DNS Server to resolve names: because we have
lots of Names
Any time a Cisco device receives a command it
doesn't understand, it will try to resolve it through
DNS by default.
R(config)#no ip domain­lookup
What happens here?

19. Having DNS
Add Commands:
R(config)#ip domain­lookup
R(config)#ip name­server
R(config)#ip domain­name

20. Network Connectivity and
Troubleshooting
R#ping <>
R#traceroute <>

21. Debugging
R#debug all
R#no debug all
R#debug ip rip
R#show processes

22. Further Readings
How to Become Network Administrator?
Part 1:
http://www.catazinelive.catreloaded.net/2012/02/01/how­to­b
Part 2:
http://www.catazinelive.catreloaded.net/2012/03/18/how­to­b