Packet drops seen with NATed GRE tunnels in SDDC 1.22

Products

• VMware NSX
• VMware Cloud on AWS

Issue/Introduction

• SDDC has been upgraded to or is on version 1.22
• Traffic encapsulated in GRE tunnels that are NATed experience packet drops.
  
  

Environment

VMware NSX 4.1.0
VMC on AWS
SDDC 1.22

Resolution

This is resolved in SDDC version 1.24.

Workaround:
• Disable flow cache. Please open a support request to have this disabled [Creating and managing Broadcom support cases]
• Avoid upgrading the SDDC to 1.22 if GRE traffic with NAT is being used.
• Route the traffic elsewhere besides the GRE tunnel.

Additional Information

Impact/Risks:
GRE traffic will be impacted if GRE packets hit a NAT rule in NSX 4.1.0.