#! /usr/bin/perl

use strict;
use Net::SNMP;
my ($session, $error) = Net::SNMP->session(
                                           -authpassword => shift || 'my_password1',
                                           -hostname  => shift || 'localhost',
                                           -username  => shift || 'usera',
                                           -version   => 'snmpv3',
                                          );

if (!defined($session)) {
    printf("ERROR: %s.\n", $error);
    exit 1;
}

my $ifOutOctets = '.1.3.6.1.2.1.2.2.1.16';
my $loopback_instance = '.1';
my $loopback_if_out = $ifOutOctets . $loopback_instance;
my $sysUpTime = '1.3.6.1.2.1.1.3.0';
my $result = $session->get_request(
                                   -varbindlist => [ $loopback_if_out ]
                                  );

if (!defined($result)) {
    printf("ERROR: %s.\n", $session->error);
    $session->close;
    exit 1;
}
printf("bytes output from loopback interface for host '%s' is %s\n",
       $session->hostname, $result->{$loopback_if_out}
      );

$session->close;
exit 0;