What is Guard Timer in ERPS?

Guard Timer in ERPS (Ethernet Ring Protection Switching) is a mechanism that prevents frequent or rapid state transitions in the network after a topology change. When a failure occurs and ERPS switches traffic to the backup path, the Guard Timer ensures a stable recovery process by delaying any new protection switch commands for a set period.

This timer prevents the ring from reacting to transient link flaps or minor disturbances, which could otherwise cause unnecessary switching between primary and backup paths. The Guard Timer value is configurable, allowing administrators to fine-tune it based on network conditions to balance fast recovery with stability.

Content created by Mike Day