Here's a good one.  Hope I can explain it well.

I have been collecting port ifInOctets and ifOutOctets (and using
mibExpr.conf to calculate LAN interface utilization) on our Cisco switches
and routers and found something rather interesting.

After speaking with our Cisco geeks, we have discovered that the SNMP Index
on switches can change for interfaces any time they add/remove a port!
(Apparently not on routers???) If on Tuesday an interface to the 4th floor
has an SNMP Index 15 and they add a new interface on Wednesday for the 2nd
floor, the 4th floors SNMP Index could now be on say Index 4!  Hence my
numbers being collected by SNMP Index will be inconsistant with that
specific!  I can walk the MIBs and find the Interface Names - these stay
with the interface even if the Index changes.

Here's my question.  If I am collecting say every 5 minutes, how can I also
collect the interface name and tie the ifInOctets & ifOutOctets to the
Interface Name so if the SNMP Index changes, I still get consistent data?

If this doesn't make sense, let me know and I'll try and explain in more
detail?