cisco learning

Basic Router Configuration

When configuring a router, certain basic tasks are performed including:
- Naming the router
- Setting passwords
- Configuring interfaces
- Configuring a banner
- Saving changes on a router
- Verifying basic configuration and router operations

The first prompt appears at user mode. User mode allows you to view the state of the router, but does not allow you to modify its configuration. Do not confuse the term "user" as used in user mode with users of the network. User mode is intended for the network technicians, operators, and engineers who have the responsibility to configure network devices.
The enable command is used to enter the privileged EXEC mode. This mode allows the user to make configuration changes on the router. The router prompt will change from a ">" to a "#" in this mode.

Hostnames and Passwords
- Router#config t
- Router(config)#enable secret class
Next, configure the console and Telnet lines with the password cisco.
- R1(config)#line console 0
- R1(config-line)#password cisco
- R1(config-line)#login
- R1(config)#line vty 0 4
- R1(config-line)#password cisco
- R1(config-line)#login

Configuring a Banner
From the global configuration mode, configure the message-of-the-day (motd) banner. A delimiting character, such as a "#" is used at the beginning and at the end of the message.
R1(config)#banner motd #
Enter TEXT message. End with the character '#'.

Verifying Basic Router Configuration
Currently in the example, all of the previous basic router configuration commands have been entered and were immediately stored in the running configuration file of R1. The running-config file is stored in RAM and is the configuration file used by IOS. The next step is to verify the commands entered by displaying the running configuration with the following command:

R1#show running-config

Now that the basic configuration commands have been entered, it is important to save the running-config to the nonvolatile memory, the NVRAM of the router. That way, in case of a power outage or an accidental reload, the router will be able to boot with the current configuration. After the router's configuration has been completed and tested, it is important to save the running-config to the startup-config as the permanent configuration file.

- Router1#copy running-config startup-config

After applying and saving the basic configuration, you can use several commands to verify that you have correctly configured the router. Click the appropriate button in the figure to see a listing of each command's output. All of these commands are discussed in detail in later chapters. For now, begin to become familiar with the output.

- Router1#show startup-config
This command displays the startup configuration file stored in NVRAM.

- Router1#show ip route
This command displays the routing table that the IOS is currently using to choose the best path to its destination networks.

- Router1#show interfaces
This command displays all of the interface configuration parameters and statistics. Some of this information is discussed later in the curriculum and in CCNP

- Router1#show ip interface brief
This command displays abbreviated interface configuration information, including IP address and interface status