garskoci,
Are the user and pass fields form values as the WWW::Mechanize example indicates, or are they more like HTTP basic auth like the LWP::UserAgent shows? I am just guessing, but what does the following code do?

#!/usr/bin/perl
use strict;
use warnings;
use WWW::Mechanize;

my $mech = WWW::Mechanize->new( autocheck => 1 );
$mech->credentials(
    '192.168.0.1:80',
    'FVS318',
    'admin' => 'secret'
);
# And then $mech->get() the same as in the LWP::UserAgent code
[download]

FWIW, take a look at WWW::Mechanize::Shell as well.

Update: Added a to autocheck