8.1.3 Received SNMP traps
You can use either of the following approaches to forward to another application the SNMP traps that NNMi receives from managed devices:
Use the NNMi SNMP trap forwarding mechanism.
Use the NNMi Northbound interface SNMP trap forwarding mechanism.
The approach to trap identification by the receiving application varies as follows:
Windows (all) and Linux (without original trap forwarding)
This description applies to the default and to the SNMPv3-to-SNMPv2c conversion forwarding options.
The NNMi SNMP trap forwarding mechanism on a Windows NNMi management server enriches each SNMP trap before forwarding it to the trap destination. The trap appears to originate from the NNMi management server. (This information also applies to a Linux NNMi management server for which the original trap forwarding option is not selected on the Trap Forwarding Destination form.)
To ensure the correct association between the trap-sending device and the event in the receiving application, the rules for these traps must be customized for the enriched varbinds. Interpret the value from the originIPAddress (.1.3.6.1.4.1.11.2.17.2.19.1.1.3) varbind. The originIPAddress value is a byte string of generic type InetAddress, either InetAddressIPv4 or InetAddressIPv6, as determined by the value of the originIPAddressType (.1.3.6.1.4.1.11.2.17.2.19.1.1.2) varbind. The rule must read the originIPAddressType varbind to determine the type of Internet address value (ipv4(1) or ipv6(2)) in the originIPAddress varbind. The rule might also need to convert the originIPAddress value to a display string.
For details about the varbinds that NNMi adds to forwarded traps, see Trap Varbinds Provided by NNMi in NNMi Help, RFC 2851, and the following file:
- Windows: %NNM_SNMP_MIBS%\Vendor\Hewlett-Packard\hp-nnmi.mib
- Linux: $NNM_SNMP_MIBS/Vendor/Hewlett-Packard/hp-nnmi.mib
Linux with original trap forwarding
A Linux NNMi management server can forward traps in the same format in which NNMi receives them. Each trap appears as if the managed device sent it directly to the trap destination, so existing trap processing configured in the receiving application will work without modification.
NNMi Northbound interface (all operating systems)
The NNMi Northbound interface enriches each SNMP trap before forwarding it to the trap destination. The trap appears to originate from the NNMi management server. To ensure the correct association between the trap-sending device and the event in the receiving application, the rules for these traps must be customized for the enriched varbinds.
The nnmiIncidentSourceNodeHostname (1.3.6.1.4.1.11.2.17.19.2.2.21) and nnmiIncidentSourceNodeMgmtAddr (1.3.6.1.4.1.11.2.17.19.2.2.24) varbinds identify the original source object.