detect missing event

[sfnet]

We have a device that sends a trap on a regular interval, and need to know if the trap does not arrive within a deisignated interval.

Any suggestions? So far none of the SNMP managers that I've looked at support this.

 

[nawlej]

What are you trying to accomplish with this trap?

___________________________________
[morse]--... ...--[/morse], Eric.

 

[sfnet]

We want to use it as a heartbeat to supervise the device.

 

[nawlej]

Becuase of the unreliability of SNMP, I wouldnt use a trap as a heartbeat monitor. Software like Cisco Information Center, or HP's Openview are capable of periodically polling devices to make sure they are still available.

___________________________________
[morse]--... ...--[/morse], Eric.

 

[lgarner]

If you can take action based on the trap's receipt, then you could try this:

Upon receipt, create a temp file.

Then run a daemon or script via cron to look for the file. If found, delete it. If not found, send an alert of some type.

 

[nawlej]

See, heres the problem with SNMP traps as heartbeats, it is unreliable. SNMP traffic gets squashed during peak periods and any other good reason where other traffic has to take priority. SNMP is one of the first types of packets to get discarded, because it is UDP. There is no guarantee whatsoever that this method would be effective at all. For availability reasons, go with a different choice.

___________________________________
[morse]--... ...--[/morse], Eric.

 

[sfnet]

I can't poll the device, as it operates "in the wild" and pulls an IP from the nearest DHCP server.

The temp file suggestion sounds like an idea.