BFD - slow-timers
The Bidirectional Forwarding Detection (BFD) slow-timers parameter is configured on a Cisco IOS device like so:
Device(config)# bfd slow-timers 14000
The above command configures the slow-timers for the BFD session to be 14000 milliseconds. The values of MinTxInt and MinRxInt correspond to the configured value of the BFD slow-timers.
The configured value can be seen in the output of the show bfd neighbors details command as shown below:
R1#show bfd neighbors details NeighAddr LD/RD RH/RS State Int 192.168.12.2 1/1 Up Up Fa0/0 Session state is UP and using echo function with 50 ms interval. OurAddr: 192.168.12.1 Local Diag: 0, Demand mode: 0, Poll bit: 0 MinTxInt: 14000, MinRxInt: 14000, Multiplier: 3 Received MinRxInt: 1000000, Received Multiplier: 3 Holddown (hits): 0(0), Hello (hits): 1000(617) Rx Count: 96, Rx Interval (ms) min/max/avg: 1/1000/868 last: 648 ms ago Tx Count: 618, Tx Interval (ms) min/max/avg: 1/1000/872 last: 708 ms ago Elapsed time watermarks: 0 0 (last: 0) Registered protocols: OSPF Uptime: 00:01:23 Last packet: Version: 1 - Diagnostic: 0 State bit: Up - Demand bit: 0 Poll bit: 0 - Final bit: 0 Multiplier: 3 - Length: 24 My Discr.: 1 - Your Discr.: 1 Min tx interval: 1000000 - Min rx interval: 1000000 Min Echo interval: 50000
- If the BFD session is down, then the BFD control packets will be sent with the slow timer interval.
- If the BFD session is up, then if echo is enabled, then BFD control packets will be sent in negotiated slow timer interval and echo packets will be sent in negotiated configured BFD interval. If echo is not enabled, then BFD control packets will be sent in negotiated configured interval.
Links:
https://forum.networklessons.com/t/bidirectional-forwarding-detection-bfd/1280/91?u=lagapidis
https://networklessons.com/cisco/ccie-routing-switching/bidirectional-forwarding-detection-bfd