use Net::Telnet;
use strict;
my $telnet = new Net::Telnet (Timeout=>10, Errmode=>'die', Prompt=>'/\S*#$/i');
my $switch=$ARGV[0];
$telnet->open($switch);
$telnet->waitfor(/Username: $/i);
$telnet->print('user');
$telnet->waitfor(/Password: $/i);
$telnet->print('geheim');
my @output=$telnet->cmd('sh mac');
print @output;