BFD Down On External Interface In router <UUID> or BFD session for peer <UUID> is down.

Products

• VMware NSX

Issue/Introduction

• BFD Down Alarm is triggered
• Packet capture on the physical NIC of the ESX where the Edge resides shows BFD packets being sent to the top of rack (TOR).

pktcap-uw --uplink [pnic] --capture UplinkSndKernel,UplinkRcvKernel --ip [ip] --dstport 3784 -o - | tcpdump-uw -enr -

[Timestamp] [MAC] > [MAC], ethertype Proto (hex), length 86: [Source IP].[Source Port] > [Destination IP].3784: BFDv1, Control, State Down, Flags: [none], length: 24
[Timestamp] [MAC] > [MAC], ethertype Proto (hex), length 86: [Source IP].[Source Port] > [Destination IP].3784: BFDv1, Control, State Down, Flags: [none], length: 24

• Packet capture on TOR shows the BFD packets being received from the T0
• Further packet capture on the TOR shows no BFD traffic is being sent from TOR to T0

Environment

VMware NSX-T Data Center
VMware NSX

Resolution

This is a third party issue and will require engagement from the Top Of Rack (TOR) Switch Vendor