FAQ:Applications 19

How do I receive traps and notifications?

Handling incoming traps is the job of a "notification receiver". The Net-SNMP suite include the tool 'snmptrapd' to act in this role. This can log traps to a file or via the syslog mechanism, forward them to another notification receiver and/or invoke a specified command whenever a particular notification is received.

Logging notifications would be done by starting snmptrapd as:

       snmptrapd -Ls 7         (log to 'LOCAL7')
           (log to syslog using 'LOCAL7')

or

       snmptrapd -f -Lo
           (log to standard output)

Invoking a command to process a received notification uses one or more 'traphandle' directives in the configuration file 'snmptrapd.conf'. A typical configuration might look something like:

       traphandle .1.3.6.1.6.3.1.5.1       /path/to/page_me up
       traphandle .1.3.6.1.4.1.2021.251.1  /path/to/page_me up
       traphandle .1.3.6.1.4.1.2021.251.2  /path/to/page_me down
       traphandle default                  /path/to/log_it

where 'page_me' and 'log_it' are the command to be run.

Forwarding notifications to another receiver would be done using similar 'snmptrapd.conf' directives:

       forward .1.3.6.1.4.1.8072.4.0.3  10.0.0.1
       forward default                  10.0.0.2

There's a tutorial with more details on the web site at the snmptrap tutorial

   FAQ:Applications
   

1. How do I add a MIB?
2. How do I add a MIB to the tools?
3. Why can't I see anything from the agent?
4. Why doesn't the agent respond?
5. I can see the system group, but nothing else. Why?
6. Why can't I see values in the <ENTERPRISE> tree?
7. The agent worked for a while, then stopped responding. Why?
8. Requesting an object fails with "Unknown Object Identifier" Why?
9. Why do I get "noSuchName" when asking for "sysUpTime" (or similar)?
10. Why do I sometimes get "End of MIB" when walking a tree, and sometimes not?
11. How do I use SNMPv3?
12. Why can't I set any variables in the MIB?
13. Variables seem to disappear when I try to set them. Why?
14. Why can't I change sysLocation (or sysContact)?
15. I get an error when trying to set a negative value - why?
16. I get an error when trying to query a string-indexed table value - why?
17. How should I specify string-index table values?
18. How do I send traps and notifications?
19. How do I receive traps and notifications?
20. How do I receive SNNMPv1 traps?
21. Why don't I receive incoming traps?
22. My traphandler script doesn't work when run like this - why not?
23. How can the agent receive traps and notifications?
24. How big can an SNMP request (or reply) be?
25. How can I monitor my systems (disk, memory, etc)?
26. Applications complain about entries in your example 'snmp.conf' file. Why?
27. OK, what should I put in snmp.conf?
28. How do I specify IPv6 addresses in tools command line arguments?