Configuring Association Between VRRP and Peer BFD to Implement a Rapid Active/Standby Switchover

Context

Only the S5720-HI, S5730-HI, S5731-H, S5731-S, S5731S-H, S5731S-S, S5732-H, S6720-HI, S6730-H, S6730S-H, S6730-S, and S6730S-S support this function.

When a VRRP group is faulty, the backup with the highest priority detects the fault and switches to the master after the Master_Down_Interval timer expires. The switchover period is at least 3s. During this switchover period, service traffic is still sent to the original master, causing loss of user traffic. In Figure 1, a peer BFD session is configured between SwitchA and SwitchB and used to rapidly detect communication faults of the VRRP group. When the BFD session detects a fault, an active/standby switchover is triggered immediately. This millisecond-level switchover reduces traffic loss.

After the fault is rectified, the VRRP group status on SwitchA and SwitchB is restored through VRRP negotiation.

A VRRP group can be associated only with a static BFD session or a static BFD session with automatically negotiated discriminators.
The master and backup in the VRRP group must work in preemption mode. It is recommended that the preemption delay be 0 on the backup and non-zero on the master.
Multiple VRRP groups can monitor a BFD session, and a VRRP group can monitor a maximum of eight BFD sessions simultaneously.

Figure 1 Association between VRRP and peer BFD to implement a rapid active/standby switchover

Procedure

Configure a static BFD session or a static BFD session with automatically negotiated discriminators. For details, see Configuring Single-Hop BFD, Configuring Multi-Hop BFD, and Configuring Static BFD with Automatically Negotiated Discriminators.
Run system-view
The system view is displayed.
Run interface interface-type interface-number.subinterface-number
The view of the sub-interface on the backup where the VRRP group is configured is displayed.
Run vrrp vrid virtual-router-id track bfd-session { bfd-session-id | session-name bfd-configure-name } peer
Association between a VRRP group and a peer BFD session is configured.
When associating a VRRP group with a BFD session, note the following points:
- If session-name bfd-configure-name is specified, a VRRP group can be bound only to a static BFD session with automatically negotiated discriminators.
- If bfd-session-id is specified, the VRRP group can be bound only to a static BFD session.
- If a VRRP group is bound to an mVRRP group, the mVRRP group maintains the VRRP group status, and the VRRP group is unable to monitor any BFD sessions.