From Net-SNMP Wiki

How do I use SNMPv3?

The simplest form of SNMPv3 request is unauthenticated and unencrypted (noAuthNoPriv). It still requires a user name (and the agent must be configured to allow unauthenticated requests from that user). Such a request would look something like:

       snmpget -v 3 -l noAuthNoPriv -u dave localhost sysUpTime.0

An authenticated request (authNoPriv) would specify a pass phrase to authenticate with:

       snmpget -v 3 -l authNoPriv -u dave -A "Open the Door"
                               localhost sysUpTime.0

A fully secure request (authPriv) would also specify the privacy pass phrase:

       snmpget -v 3 -l authPriv -u dave -A "Open the Door"
                       -X "Bet you can't see me"  localhost sysUpTime.0

In practise, most of these would probably be set via configuration directives in a personal $HOME/.snmp/snmp.conf file (note, not the agent's snmpd.conf file). The equivalent settings for the third example would be:

       defSecurityName         dave
       defSecurityLevel        authPriv
       defAuthPassphrase       "Open the Door"
       defPrivPassphrase       "Bet you can't see me"

If the AuthPassphrase and the PrivPassphrase are the same, then you can use the setting

               defPassphrase   "Open the Door and see me"

instead.

See the AGENT section for how to configure the agent to respond to SNMPv3 requests.

   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 get a string-indexed table value - why?
17. What quotes should I use for string index values?
18. How do I send traps and notifications?
19. How do I handle traps and notifications?
20. My traphandler script doesn't work when run like this - why not?
21. How big can an SNMP request (or reply) be?
22. How can I monitor my systems (disk, memory, etc)?
23. Applications complain about entries in your example 'snmp.conf' file. Why?
24. OK, what should I put in snmp.conf?
25. How do I specify IPv6 addresses in tools command line arguments?