Configuring IPv6 FRR

Applicable Environment

After IPv6 FRR is configured, if a link fault is detected at a lower layer (physical layer or link layer), the fault is reported to the upper-layer routing system. Meanwhile, packets are forwarded using a backup link to minimize the impact of the link fault on services. IPv6 FRR is applicable to services that are very sensitive to the delay and packet loss on an IPv6 network.

IPv6 FRR enables routes generated by different routing protocols to back up each other, which may cause a loop. Therefore, exercise caution when configuring IPv6 FRR.

With IP FRR, traffic is switched to a backup link if the primary link fails and switched back when the primary link recovers. If the inbound and outbound interfaces reside on different boards, packet loss may occur during the switchback. The packet loss duration varies with the service volume and CPU usage. To prevent the packet loss, perform any of the following operations:

• Run the timer spf command in the IS-IS view.
• Run the spf-schedule-interval (OSPFv3) command in the OSPFv3 view.
• Run the route-select delay command in the BGP view.

Pre-configuration Tasks

Before configuring IPv6 FRR, complete the following tasks:

• Configuring link layer protocol parameters and assigning IPv6 addresses to interfaces to ensure that the link layer protocol on the interfaces is Up

• Configuring IPv6 routes destined for the same destination address but discovered by different routing protocols