FAQ:Applications 07

The agent worked for a while, then stopped responding. Why?

Assuming that the agent hasn't crashed completely, the most likely explanation is that it's simply overloaded, and is taking longer to respond than the querying tool is waiting. Since the agent handles each request in turn, without regard to earlier activity, and most tools will retry a request when it times out, the list of outstanding requests can grow longer and longer.

To determine whether this is the cause, try leaving the agent undisturbed for a while, and then probe it using a single 'snmpget' or 'snmpgetnext' request, specifying a longer timeout (e.g. '-t 120'). This should give the agent time to handle the request first time round, and avoids overloading it with duplicate requests.

This is not a full solution, of course, but at least it should allow you to isolate the offending portion of the tree. The developers may then be able to offer a more long-term solution.

   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?