Monitoring shows interface index inconsistencies after router reloads. What fixes persistent ifIndex changes across reboots?

The snmp ifindex persist command, when configured globally, ensures that the SNMP ifIndex values for interfaces remain consistent across router reloads. This is crucial for network monitoring systems that rely on these indices to track interface performance and status over time. Without persistence, ifIndex values can change after a reboot, causing monitoring systems to lose historical data or incorrectly associate data with the wrong interface. Configuring snmp ifindex persist on physical interfaces only would not cover logical interfaces, which also need consistent indexing. Clearing logical interfaces with snmp ifindex clear would reset the indices, not persist them. Triggering a new snmpwalk from the monitoring system might temporarily resolve the issue by re-discovering OIDs, but it doesn't prevent future inconsistencies after another reboot.