Absence of BFD Echo packet loop back to external physical switch in BFD Echo mode

Products

• VMware NSX

Issue/Introduction

Symptoms:

• NSX is deployed with BFD enabled. 
• The external physical switch is configured in BFD Echo Mode, meaning it sends BFD Echo packets to the NSX Edge device. The switch expects the NSX Edge to loop back (forward) these Echo packets as a reply. 
• However, the NSX Edge does not forward the Echo packets back to the switch.

Environment

VMware NSX 4

Cause

NSX does not support BFD Echo mode for the time being.

Resolution

Please do not use BFD Echo mode for the time being.

Additional Information

Reference from other vendor for BFD Echo mode

https://www.cisco.com/c/en/us/td/docs/ios/12_0s/feature/guide/fs_bfd.html