Networking Schemes for IP Network Reliability

Faults on an Intermediate Node or on the Link Connected to It - LDP FRR/TE FRR

In Label Distribution Protocol (LDP)/traffic engineering (TE) scenarios, if there are intermediate devices between PEs, use BFD to monitor the link between the PEs.

Fault on the Local Link - P2MP TE FRR

Fast reroute (FRR) can protect P2MP and P2P TE tunnels. TE FRR establishes a bypass tunnel to protect sub-LSPs. If a link fails, traffic switches to the bypass tunnel within 50 milliseconds.

Fault on the Link Between PEs

BFD can be used to monitor the link between PEs.

Fault on the Remote PE - VPN FRR

In virtual private network (VPN) FRR scenarios, BFD can be used to detect the connectivity faults between PEs.

Fault on the Downlink Interface on a PE - IP FRR

In IP FRR scenarios, when the primary path between a CE and a PE fails, traffic switches to the bypass path.