Packets sent by the Cisco Telemetry Broker are dropped by the vDR

Products

• VMware NSX

Issue/Introduction

• The Cisco Telemetry Broker(CTB) is connected to an NSX Segment and the Segment is attached to an NSX Gateway
• The tcpdump on the CTB suggests that the packets are leaving the CTB
• The packets are dropped on the ESXi kernel and not leaving the ESXi uplink 
• The RPF stats on the host vDR LIF is found to be incrementing
  esx-04.corp.local> get gateway 0316####-ca5f-####-9a90-d6ee####e0ab interface 2827####-764b-####-8210-9b9d####8526 stats | find RPF
RPF Failure Drops                                 : 71


Environment

VMware NSX

Cause

URPF on the ESXi host vDR drops packets when they are received with source IP that is not in the same subnet as that of the connected Segment's subnet.

Resolution

This is an expected behavior and to resolve this the configuration must be changed.

The 'URPF Mode' setting under Segments> Advanced Settings should be set to 'None' to allow the vDR to route the traffic further instead of dropping it.

Additional Information

Ingress Filtering for Multihomed Networks