#!/usr/bin/ruby -w

require 'net-snmp'

Net::SNMP::Session.open(:peername => 'example.com',
                        :version => '3',
                        :security_level => Net::SNMP::Constants::SNMP_SEC_LEVEL_AUTHPRIV,
                        :auth_protocol => :md5,
                        :priv_protocol => :des,
                        :username => 'user',
                        :password => 'xxxxxx') do |sess|
  pdu = sess.get('.1.3.6.1.4.1.2021.4.5.0')
  pdu.print
end