<p>I'm querying a bunch of information from cisco switches using SNMP.  For instance, I'm pulling information on neighbors detected using CDP by doing an snmpwalk on .1.3.6.1.4.1.9.9.23</p>

<p>Can I use this OID across different cisco models?  What pitfalls should I be aware of?  To me, I'm a little uneasy about using numeric OIDs - it seems like I should be using a MIB database or something and using the named OIDs, in order to gain cross-device compatibility, but perhaps I'm just imagining the need for that.</p>

It is very consistent.
Monitoring tools depend on the consistency and the MIBs produced by Cicso rarely change old values and usually only implement new ones.
Check out the Cisco
OID look up tool
.
Notice how it doesn't ask you what product the look up is for.
-mw