For a while now, security scanning software and users have been triggering an onslaught of %SNMP-3-AUTHFAIL messages in our device logs. This rather annoying message often obscures other events that may be more important. Old mentality would tell you to simply create a logging discriminator and be done with it. However, I recently learned of a little undocumented gem in IOS that saves the day:

hostname(config)#no logging snmp-authfail

Do not trust the almighty ‘?‘ command. It will not show up as a valid option. However, when actually executing the command, it has worked in every IOS case I have tried.

Jonathan Voss - Mar 23, 2011