BFD Protocol

BFD protocol when enabled detects connectivity failures faster and send notification to routing protocols like BGP, OSPF, static routes so that they can bring down routes faster. BFD will be run on top of routing protocols because routing protocols take longer time to detect peer down detection. BFD runs with aggressive timers to detect the link failure faster.

Problem

BFD is not coming between VOS and peer devices

Troubleshoot

1) Check status of BFD from director monitoring dashboard

2) Check Rx packets to confirm BFD packets are received from Peer. Use below VOS command to check IN BFD packets

3) Make sure BFD configuration for transmit interval, receive interval matches between both VOS and peer device.

4) Make sure VOS is sending BFD packets out of interface. Use VOS tcpdump on egress interface to confirm BFD packets are indeed going out of the VOS.

5) If VOS is sending BFD packets out of interface and remote device is not sending back, troubleshoot peer device. Make sure BFD packets sent by VOS is making to BFD module on peer device. Use peer device debugging/troubleshooting guide.

6) Make sure My Discriminator and Your Discriminator matches between both VOS and remote device