If you are receiving timeouts it is most likely the default prompt matching string is not matching your router's prompt.

Please read the documentation for Net::Telnet. To make your life easier, specifically look deeper at the likes of:

  $t = new Net::Telnet (Timeout => 10,
                        Prompt => '/bash\$ $/');
[download]

Note that you'll have to change the Prompt regexp to something that matches your router's prompt.. if you provide examples of what your router's prompts look like someone can suggest a suitable regexp.

I just wanted to add: the default prompt (in the documentation for Net::Telnet) is /[\$%#>] $/ (which probably doesn't match a typical IOS prompt).

Note that there also exists a Net::Telnet::Cisco module if you don't want to go to the (relatively simple) trouble of configuring your own prompt regexp.

monarch's comment is spot on. While I use the Net::Telnet::Cisco module I made a quick script just using Net::Telnet. Below is a script that logs into a 3750 switch and performs show clock. the switch's prompt is 3750G>. Without the prompt, the script simply times out.

use Net::Telnet;            # use the telnet module

my $host = '3750g';

my $t = new Net::Telnet (Timeout => 10,
                         Prompt  => '/3750G\>/',
                        );
$t->open($host);
$t->login($user,$pass);

@data = $t->cmd("show clock");

print "data is @data";

$t->close;
[download]

Here is the output of the script: data is 19:21:11.575 UTC Tue Aug 21 2007 I hope you can add the Net::Telnet::Cisco module in the future. It greatly simplifies life if you have a bunch of these to keep track of.

DB<5> x @data
[download]