Posting this here because I’ll forget, and it might be needed for $WORK, even with my efforts into cfengine-ing the setup.
So, after licensing issues with MIB’s, Debian Squeeze stopped shipping with all of them; which means that a whole metric fuckton are missing if you try and do anything.
It also means that snmpd will not honour the extend directive, as it can’t find the MIB’s, but without displaying any error messages in the logging. Fuckers.
The fix to this is to install the snmp-mibs-downloader package, which automates pulling them all down and putting them in the right places.
That’s wasted two evenings hacking, not to mention countless hours at $WORK SNMP probing kit, grumble..