Set SNMP port to something different

[Köhne]

We are monitoring some servers in a DMZ.
We need to forward the SNMP traps to a SNMP Receiver, which resides on the same system as the HPSIM server. Therfore we have to switch the SNMP port to which the SNMP traps are sent to somethin different than 162, because the HPSIM server is listening to this port.
Our SNMP receiver is configurable and we can select any port we like.
We found no information in the documentation.

Any suggestions?

[Andrew_346]

Why are you running another SNMP trap application other than SIM? Provided you import the MIBs for any other SNMP devices you have, SIM is a very capable SNMP trap.

[Rob Buxton · Accepted solution]

The HP Agents just uses the default SNMP sender and for Windows there doesn't appear to be a way of changing the port.

A possible solution would be to send it to HPSIM and then use theEvent Handling process to run a Custom Command procedure that sent an SNMP Trap to a target using a different port.

For this you'd need to find an SNMP Trap sending utility that allows using a different port number.

[Köhne]

Hello Andrew,

we use HPSIM to collect the Traps from our monitored Windows Servers. We need to forward those traps to a tivoli SNMP adapter/receiver. This Tivoli adapter is a very small peice of software and we would like to run it on the HPSIM serves host.
We can select the IP-prot on which the tivoli adapters listens for SNMP traps. Now we need a way to define the IP-port to which HPSIM sends its traps.

[Köhne]

Hello Rob,

we would like to use the standard HPSIM mechanism to forward SNMP traps (and internal HSPIM servers traps (polling)).
A wrapper for the event handling facility would be inconvenient.

[Rob Buxton]

Not sure how you'll be able to forward traps to the same server without using a separate utility.

[Köhne]

Hello Rob,
this is the idea:

1. Monitored Servers:
Sending on ephemeral to HPSIM:162
2. HPSIM
Listening on 162
3. HPSIM
Sending on ephemeral to 5555
4. SNMP Receiver
Listening to 5555
(Port 5555 is just an example.)

Thus we would be able to operate the whole stuff on one box.

It is not unusual to use a different port than 162 to listen to SNMP traps. Of course the sender must be configurable.

[Rob Buxton]

The HP SNMP Forwarder uses a similar mechanism to the custom command.
You'd still need to set up the Event Handling task to then forward the SNMP Trap. But using that approach I don't think you can change the SNMP Port which you would need to do as the additional listener is on the same box.

That's why I suggested using the Custom Command, a similar Event Handling task except that it calls a script which runs an SNMP Sender Utility that is configurable.
But I've never done this and the bit that would need checking is whether the SNMP OID can be passed as a parameter through to the Custom Command.

The SNMP Sender on the HPSIM Server is also used by the agents on that server to send traps to HPSIM. So that's another thing to consider.

[Köhne]

We would not only need the enterpise OID but olso the OIDs of the trap variables. We would need a "real" forward of the traps.
Otherwise we would change the SNMP trap formats somehow and we would not be able to use a standard SNMP receiver which is based on MIB-files.
Thanks a lot for your answer.