Question

A network administrator configured SNMPv3 on a router so the NMS can poll interface statistics. The NMS authenticates successfully and can retrieve system-level data (sysName, sysUpTime), but every attempt to walk the IF-MIB (ifTable) returns no data for those objects. The relevant configuration is:

snmp-server view LIMITED system included
snmp-server group MONITOR v3 priv read LIMITED
snmp-server user NMSUSER MONITOR v3 auth sha CISCO123 priv aes 128 CISCO456

What is the most likely cause of the missing IF-MIB data?

Accepted Answer

The SNMPv3 view LIMITED only includes the system subtree, so the ifTable OIDs are outside the readable view

Answer

The user NMSUSER is using AES-128 privacy, which does not support IF-MIB object retrieval

Answer

The group MONITOR must be configured with the 'write' permission to return interface counters

Answer

The engine ID on the NMS and router are mismatched, blocking table-based OIDs