FAQ:Applications 17

How do I handle traps and notifications?

Handling received traps is done using the tool 'snmptrapd'. This can log these traps via the syslog mechanism:

       snmptrapd -Ls 7         (log to 'LOCAL7')
       

printed to standard output

       snmptrapd -f -Lo

or pass them to an external command. This last approach uses a 'traphandle' directive in the configuration file 'snmptrapd.conf'. A typical file might look something like:

       traphandle .1.3.6.1.6.3.1.5.1       page_me up
       traphandle .1.3.6.1.4.1.2021.251.1  page_me up
       traphandle .1.3.6.1.4.1.2021.251.2  page_me down
       traphandle default                  log_it

where 'page_me' and 'log_it' are the command to be run. (You probably need to specify full pathnames, to ensure that the commands will be found. They're just short here for readability).

Note that the first entry uses the OID corresponding to the SNMPv1 'coldStart' trap. See the co-existence RFC (RFC 2576) for details of mapping SNMPv1 traps to SNMPv2 OIDs.

Starting with net-snmp 5.3, snmptrapd will no longer accept all traps by default. It must be configured with authorized SNMPv1/v2c community strings and/or SNMPv3 users. Non-authorized traps/informs will be dropped. Please refer to the snmptrapd.conf(5) manual page for details.

There's a tutorial with more details on the web site at http://www.net-snmp.org/tutorial-5/commands/snmptrap.html

   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?