The Cisco router is a diskless computer and must therefore be reconfigured via remote login. The Cisco Internetworking Operating System (Cisco IOS) is an enormously complicated software system with numerous options. Although we were principally interested in only a few of the options available in this system, below is a brief overview of how it works and what some of the possibilities are...
Once logged into the router with an authorized password, the user level prompt Router> appears. To enable privileged commands to be executed (similar to root on a UNIX system), the command enable is given, followed by an authorized password. This will return the new prompt Router#.
From this priveleged level, since we were interested in reconfiguring the router, we issued the command erase startup-config to bring the router into the setup mode. From here we were prompted to enter the (Cisco) system configuration and set up global and interface parms. The quintessential information required for this operation, of course, was what kind of interfaces to configure and the correct internet address(es) and subnet mask. Sample screens of this process are illustrated below:
--- System Configuration Dialog ---
At any point you may enter a question mark '?' for help. Refer to the 'Getting Started' Guide for additional help. Use ctrl-c to abort configuration dialog at any prompt. Default settings are in square brackets '[]'.
Would you like to enter the initial configuration dialog? [yes]:
First, would you like to see the current interface summary? [yes]:
Any interface listed with OK? value "NO" does not have a valid configuration
| Interface | IP-Address | OK? | Method | Status | Protocol |
|---|---|---|---|---|---|
| TokenRing0 | unassigned | NO | not set | down | down |
| Ethernot0 | unassigned | NO | not set | down | down |
| Serial0 | unassigned | NO | not set | down | down |
| FddiO | unassigned | NO | not set | down | down |
Enter host name [Router] : sandbox
Enter enable password: shovel
Enter virtual terminal pansword:pail
Configure SMW Network Management?[no]:
Configure IF? (yes]:
Configure IORP routing? [yes]:
Your IGRP autonomous system number [1]:20
Configure DECnet? [no]:
Configure XNS? [no]:
Conf iqure Novell? [no] :yes
Configure Apollo? [no]:
Configure AppleTalk? tno]:yes
Multizone networks? [no]:yes
Configure Vines? [no]:
Configure bridging? [no]:
Configuring interface parameters:
Config-uring interface TokenRing0:
Is this interface in use? [yes]:
Tokenring ring speed (4 or 16)? [16]:
Conf ig-ure IP on this interface? [no] :yes
IP address for this interface:131.108.92.67
Number of bits in subnet field [0]:
Class B network is 131.108.0.0, 0 subnet bits; mask is 255.255.0.0
Configure Novell on this interface? [no]: yes
Novell network number [1]:
Configuring interface serial0:
Is this interface in use? [yes]:
Configure IP on this interface? [yes]:
Configure IP unnumbered on this interface? [no]:
IP address for this interface:131.108.97.67
Number of bits in subnet field [0]:
Class B network is 131.108.0.0, 0 subnet bits; mask is 255.255.0.0
Configure Novell on this interface? [yes]: no
Configuring interface Serial1:
Is this interface in use? [yes]: no