Crash Course Routing TCL scripts

Objectives

Use Tcl scripts to verify full connectivity.

Identify causes of failures.

Background

The Cisco IOS Scripting feature provides the ability to run Tool Command Language (Tcl) commands from the Cisco IOS command-line interface (CLI). Tcl scripts can be created to accomplish routine and repetitive functions with Cisco IOS-based networking devices. In this lab, you create and execute a Tcl script that sends pings to multiple IP addresses in the network to test overall network connectivity.

Cisco IOS Release 12.3(2)T and later supports Tcl scripting.

Required Resources

2 routers (Cisco 1841 with Cisco IOS Release 12.4(24)T1 Advanced IP Service or comparable)

Serial and console cables

This lab uses Cisco 1841 routers with Cisco IOS Release 12.4(24)T1 and the advanced IP image c1841-advipservicesk9-mz.124-24.T1.bin. Other routers (such as a 2801 or 2811) and Cisco IOS Software versions can be used if they have comparable capabilities and features. Depending on the router model and Cisco IOS Software version, the commands available and output produced might vary from what is shown in this lab.



Step 1: Configure initial settings.

Copy and paste the following initial configurations for R1 and R2.

Router R1

hostname R1
!

interface loopback 1

ip address 10.1.1.1 255.255.255.252
!
interface loopback 2
ip address 10.1.2.1 255.255.255.252

!

interface loopback 3
ip address 10.1.3.1 255.255.255.252
!
interface loopback 4

ip address 10.1.4.1 255.255.255.252

!
interface serial 0/0/0

ip address 10.100.12.1 255.255.255.252 clock rate 64000

bandwidth 64 no shutdown
!
router rip version 2 network 10.0.0.0 no auto-summary

!
end

A 30-bit subnet mask (255.255.255.252) is used for the serial links in this lab. However, starting with IOS 12.2(4)T, the 31-bit subnet mask (255.255.255.254) is supported on IPv4 point-to-point interfaces (per RFC 3021), requiring only 2 IP addresses per point-to-point link (.0 and .1). The IP Unnumbered feature can also be used to conserve IP addresses.


Router R2

hostname R2

!
interface loopback 1
ip address 10.2.1.1 255.255.255.252
!

interface loopback 2

ip address 10.2.2.1 255.255.255.252
!
interface loopback 3
ip address 10.2.3.1 255.255.255.252

!

interface loopback 4
ip address 10.2.4.1 255.255.255.252
!

interface serial 0/0/0 bandwidth 64


.


no shutdown
!

router rip version 2 network 10.0.0.0 no auto-summary

!
end