Why can't I get SNMP information from a device?

Monitor one requires that SNMP be available and configured to display traffic information. In order of simplest to most complex, here is a list of reasons that Monitor one might not get SNMP information from a device:

  1. Wrong DNS name/IP address (not likely, but we have to mention it).
  2. No connectivity. Can you ping the device from the Monitor one station?
  3. No SNMP agent on the device. Many devices or computers have optional SNMP capabilities that must be installed separately.
  4. In a custom Shooter, have you specified the OID and Instance properly?
  5. Wrong Community string (have you tried 'public' ?)
  6. Access lists: does the equipment only allow SNMP access from certain addresses?
  7. Firewalls: does a firewall block the SNMP port between your Mac and the equipment?
  8. Bugs in the SNMP agent on the equipment. Monitor one uses SNMP Get-Next-Requests in several places. We've seen certain equipment that fails when queried this way.