FAQ:Applications 10

Why do I sometimes get "End of MIB" when walking a tree, and sometimes not?

This depends on which MIB modules are supported by the agent you are querying and what you're asking for.

Recall that a tree is walked by repeatedly asking for "the next entry" until all the values under that tree have been retrieved. However, the agent has no idea that this is what's happening - all it sees is a request for "the next entry after X".

If the object X happens to be the last entry in a sub-tree, the agent will provide the next object supported (as requested) even though this will be in a different subtree. It's up to the querying tool to recognise that this last result lies outside the area of interest, and simply discard it.

If the object X happens to be the last entry supported by the agent, it doesn't have another object to provide, so returns an "end of MIB" indication. The Net-SNMP tools report this with the message above.

But in either case, the actual information provided will be the same.

   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?