FAQ:Applications 18

My traphandler script doesn't work when run like this - why not?

If a traphandler script works fine when run manually from the command line, but generates an error when triggered by an incoming notification, then this is probably down to one of two likely causes.

Firstly, the interactive shell environment may not be precisely the same as that for programs executed by the snmptrapd daemon. In particular, it's quite possible that the PATH environmental variable may not include all the additional directories that are commonly set up for a personal login configuration. To avoid this problem (particularly for traphandler shell scripts), it's worth giving the full path to all programs used within the script.

Secondly, the snmptrapd daemon may not always recognise the appropriate interpreter to use for a particular trap handler. If this is the case, then you can specify this interpreter explicitly as part of the trap handle directive:

       traphandle default /usr/bin/perl /usr/local/bin/log_it

Note that in this case, it's almost certain that you'll also need to give the full path to the traphandle script (as shown)

   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?