Cisco IOS Cookbook, 2nd Edition

Changing the Configurations of Many Routers at Once

Problem

You want to make a configuration change to a large number of routers.

Solution

The Expect script in Example 1-2 makes the same configuration changes to a list of routers by using Telnet. When it finishes running, the script produces a status report to identify which devices, if any, failed to update properly. No arguments are required or expected.

Example 1-2. rtrchg.exp

#!/usr/local/bin/expect # # rtrcfg.exp -- a script to perform mass configuration changes to # a list of routers using telnet and Expect # # # Set Behavior set tftp "172.25.1.1" set workingdir /home/cisco/rtr # puts stdout "Enter user name:" gets stdin userid system stty -echo puts stdout "Enter login password:" gets stdin vtypasswd puts stdout "\nEnter enable password:" gets stdin enablepwd system stty echo system "cp $workingdir/NEWCONFIG /tftpboot/NEWCONFIG" set RTR [open "$workingdir/RTR_LIST" r] set LOG [open "$workingdir/RESULT" w] while {[gets $RTR router] != -1} { if {[ string range $router 0 0 ] != "#"} { set timeout 10 spawn telnet; expect "telnet>"; send "open $router\n" expect { {Username} { send "$userid\r" expect { {*Password*} { send "$vtypasswd\r" } } } {Password} { send "$vtypasswd\r" } timeout { puts $LOG "$router - telnet failed" close; wait; continue } } expect { {Password} { puts $LOG "$router - vty login failed" close; wait; continue } {Username} { puts $LOG "$router - vty login failed" close; wait; continue } {>} { puts $LOG "$router - ...