Template:FAQ:Applications 08

If a general snmpwalk shows the entry, but asking for it more specifically gives a "sub-identifier not found:" or "Unknown Object Identifier" error, then that's a problem with the tool, rather than the agent.

Firstly, make sure that you're asking for the object by the right name. Object descriptors are case-sensitive, so asking for 'sysuptime' will not be recognised, but 'sysUpTime' will.

Secondly, the object may be defined in a MIB that hasn't been loaded. Try loading in all the MIB files:

       snmpget -m ALL -v1 -c public localhost sysUpTime.0

(though if snmpwalk displays the object by name, this is unlikely to be the cause).

Thirdly, earlier versions of the UCD software expected "full" paths for object names, either based at the root of the whole MIB tree (".iso.org.dod.internet.mgmt.mib-2.system.sysUpTime") or the 'mib-2' subtree ("system.sysUpTime"). Try:

       snmpget -v1 -c public myhost system.sysUpTime.0

These earlier versions of the tools may take a command-line option '-R' or '-IR' (depending on vintage) to invoke this "random-access" mode. Note that snmptranslate still requires "random-access" to be specified explicitly - all other command tools now use this mode by defaults.

All versions of the UCD and Net-SNMP tools accept the syntax

       snmpget -v1 -c public myhost RFC1213-MIB::sysUpTime.0

to denote a particular object in a specific MIB module. Note that this uses the name of the module, not the name of the file. See the second question in this section for the distinction.