GRES: Delay in removing subscriber routes after GRES

For a subscriber network in which either nonstop active routing (NSR) or graceful restart has been configured, you can configure the router to wait for 180 seconds (3 minutes) before removing access routes and access-internal routes after a graceful Routing Engine switchover (GRES) takes place. This 3-minute delay provides sufficient time for the appropriate client process (jpppd or jdhcpd) or routing protocol process to reinstall the access routes and access-internal routes before the router removes the stale routes from the forwarding table. As a result, the risk of traffic loss is minimized because the router always has available subscriber routes.