1. Configuring a Router
Module 3
Semester 2

2. Router Configuration Tasks
Name a router
Set passwords
Examine show commands
Configure a serial interface
Configure an Ethernet interface
Execute changes to a router
Save changes to a router
Configure an interface description
Configure a message-of-the-day banner
Configure host tables
Understand the importance of backups and documentation

3. Router Modes
All configuration changes are made from Global Config mode
Ctrl-Z or end
returns to Privileged EXEC mode
exit
Go back one step

4. Configure Hostname Required if name resolution is to be used
Not essential for the functioning of our routers but is important

5. Configuring passwords
An important feature
security
telnet (vty) will not work without a password set
Line console 0
sets login password for User EXEC mode
Enable password xxx
sets login password for Privileged EXEC mode
Enable secret
sets encrypted password for Privileged EXEC mode
(strong encryption)

6. Show Commands
show history - Displays a history of commands that have been entered
show flash - Displays information about flash memory and what IOS files are stored there
show version - Displays information about the currently loaded software version along with hardware and device information
show arp - Displays the ARP table of the router
show protocols - Displays the global and interface-specific status of any configured Layer 3 protocols
show startup-config - Displays the saved configuration located in NVRAM
show running-config
show interfaces – Displays statistics for all interfaces on a router.
Router#show interfaces serial 0/1
show controllers serial - Displays information that is specific to the interface hardware. This command must also include the port or slot/port number of the serial interface.
Router#show controllers serial 0/1
show clock - Shows the time set in the router
show hosts - Displays a cached list of host names and addresses
show users - Displays all users who are connected to the router

7. Configuring an interface

8. Configuring an Ethernet Interface

9. Configuring a Serial Interface
Fast Ethernet Interface
Router(config)# interface fastethernet 0/0
Router(config-if)# ip address
Router(config-if)# no shutdown
Serial Interface (DCE) (no clock for DTE)
Router(config)# interface serial 0/0
Router(config-if)# ip address
Router(config-if)# clock rate 56000

10. Configuring Interface Descriptions
An interface description should identify important information such as a router, a circuit number, or a specific network segment.

11. The Login Banner The Banner is seen when someone attempts to login
Important to let user know it is a private system

12. Login Banner MOTD Configured from Global Config mode
Use the Banner MOTD command
Use delimiters (#) to indicate start and end of message

13. Two Choices Host Name Resolution DNS Hosts Table Dynamic
(not available in our lab)
Hosts Table
Static entries
Used in our lab situation

14. Configuring Hosts Tables
The Host table contains:
Name
IP address of each router in the network
The host name in a command will be resolved to an IP address if the name is found in the table
i.e. ping Auckland
is translated to ping (if the hosts below entered)
Host tables only apply to the the local router

15. The copy running-config tftp Command
Backing up Configuration Files

16. The copy tftp running-config Command
Restoring Configuration Files from a TFTP Server

17. Changing Router Configuration

18. Configuration Standards
Configuration Standards may specify:
How the files are stored
Where the files are stored
Naming conventions
Who has access
Coding standards – e.g. comments, sections, etc
Interface descriptions