Explains how the Fast Reroute recirculation avoidance mechanism eliminates packet recirculation during failover events, and describes its benefits for PE router deployments by improving bandwidth efficiency, preserving line-rate throughput, and reducing congestion and traffic loss during successive FRR events.
Fast Reroute (FRR) recirculation avoidance mechanism is a core routing enhancement that
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eliminates packet recirculation during FRR events,
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improves bandwidth efficiency and prevents traffic loss in PE edge router deployments, and
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maintains line-rate throughput by optimizing the forwarding chain during failover scenarios.
| Feature Name |
Release Information |
Feature Description |
|---|---|---|
| Fast Reroute recirculation avoidance |
Release 26.2.1 | Introduced in this release on: Fixed Systems (8200 [ASIC: Q200]); Centralized Systems (8600 [ASIC:Q200]); Modular Systems (8800 [LC ASIC:Q200]) You can now eliminate packet recirculation during Fast Reroute events in PE routers. The feature ensures that traffic switches to backup paths without requiring recycle operations during both first and subsequent FRR events. Previously, traffic switched to backup paths during FRR events that required one or more recycle passes. This increased bandwidth and reducing efficiency. |
FRR recirculation avoidance eliminates packet recirculation during FRR events in PE edge router deployments, improving bandwidth efficiency and reducing traffic loss.
Previously, when the primary transit path failed during the first FRR event, the router redirected traffic to a backup path that required one packet recycle. If a second FRR event occurred, traffic was redirected to another backup path that required an additional recycle. These recirculation steps consumed NPU bandwidth and, under high load conditions, could lead to congestion and potential traffic drops due to limited recycle port capacity.