(Optional) Configuring the BFD WTR Time

The status change of the static BFD session will take effect after the Wait to Recovery (WTR) time, which avoids the affects caused by BFD session flapping on upper-layer protocols.

Context

If a BFD session flaps, BFD-related applications will be frequently switched between active and standby devices. To avoid this case, you can configure the WTR time for the BFD session. When a BFD session changes from Down to Up, the BFD will notify this status change to upper-layer applications only after the WTR time.

Procedure

Access the system view.
```
system-view
```
Access the BFD session view.
```
bfd cfg-name
```
Set the WTR time for the BFD session.
```
wtr wtr-value
```
By default, the time of waiting for recovery of the BFD session is 0, indicating no waiting.

The BFD session is bidirectional. The detection is performed by BFD sessions set up on both ends respectively. If WTR is needed, configure it on two ends manually. Or, when the status of the session on one end changes, the applications on both ends can find that the status of the BFD sessions is inconsistent.
Commit the configuration.
```
commit
```
To change session parameters (by using the min-tx-interval, min-rx-interval, detect-multiplier, tos-exp, wtr, or description command) after a BFD session is created, you must run the commit command. In this case, the configurations can take effect.