ICMP and SNMP polling coordination

The IP Manager links its ICMP and SNMP pollers so that the SNMP poller does not send requests to any SNMP agent address that the ICMP poller determines to be unreachable. IP addresses that are unresponsive to ICMP polls are added to a “do not poll” list, which the SNMP poller checks before sending SNMP requests.

The checking process is as follows:

• If an SNMP agent address is on the “do not poll” list, the SNMP poller does not send a request to that address.

• If an SNMP agent has multiple IP addresses, the SNMP poller checks for each address in the “do not poll” list.

  • For an address that does not appear in the list, the SNMP poller sends a request to that address.

  • If all addresses for an agent are on the list, the SNMP poller deems the agent as unreachable and temporarily suspends sending SNMP requests to that agent.

    As soon as an agent’s IP address becomes responsive, as determined by the ICMP poller, the address is removed from the list, and SNMP polling resumes.