Ubuntu 10.10 (and I assume other Debian based distributions too) come without the IETF MIB files installed with the default Net-SNMP package.
This means you can’t query OIDs directly by name anymore, such as “system.sysUpTime.0”.

The easiest way to install the missing MIB files, is using the snmp-mibs-downloader package:

$ sudo apt-get install snmp-mibs-downloader $ sudo download-mibs $ sudo sed -i 's/^mibs/#mibs/g' /etc/snmp/snmp.conf