If the polling of the candidate system is successful, the IP Manager reads the SNMP response to learn the system name (sysName), system description (sysDescr), system OID (sysObjectID), and other system-related information of the candidate system.

The IP Manager then performs the following tasks to determine whether the candidate system matches the filter:

  • Compares the retrieved system description against the System Description field in the filter.

  • Compares the retrieved system OID against the SystemOID field in the filter.

  • Maps the retrieved system OID to an OID in the oid2type files to identify the system’s type, and then compares that type against the “System Types” field in the filter.

  • Passes the candidate system’s IP address to the local name resolution service to resolve the address to a name, and then compares that name against the “System Name” field in the filter.

    The filter matching is shown in “Phase 2: Determine the destination of the candidate system” on page 149.

    If the candidate system matches the filter, the system enters Phase 3 of the discovery process. If the candidate system does not match the filter, the system is compared against the core fields of the next lower priority filter.

    Whether the candidate system matches this filter or another filter in the stack of discovery filters, the IP Manager assigns to the system the SNMP port, SNMP version, access mode, and read community string values that the IP Manager used to successfully poll the system.

    If a candidate system does not match the core fields of any discovery filter, the IP Manager discards the system.