The time taken for a network to converge after any kind of link failure is an important factor in preventing major disruptions in the network. The Static Prefix Independent Convergence (Static PIC) feature reduces the time taken for the network to converge for static routes when there is a failover in primary static nexthop to backup static nexthop.
Static PIC is supported on all SLX platforms.
As seen in the following image, static routes are configured to reach a single Edge Gateway from each border leaf router. There is a redundant pathway for failover where the external network is connected through two Edge Gateways. In the case where the link between Border-Leaf 1 and Edge Gateway 1 fails, the traffic is automatically switched to the ICL link and then switched to the Edge Gateway 2.
As seen in the following image, static routes are configured to reach the Edge Gateway from the border leaf routers per VRF. Generally, the link from a border leaf to the Edge Gateway is a port channel with ECMP links. When all ECMPs in the port channel towards both the Edge Gateways go down, the traffic is immediately switched to the ICL link and then switched to the other Border Leaf.
