VM ping failed between two sites after route-based IPSec VPN configuration due to overlapping subnets

Products

• VMware NSX

Issue/Introduction

• Configured route-based IPSec VPN and tunnel shows up, but VMs between two IPSec VPN sites ping failed.
• The same remote subnet configured in local site under same Tier-1 Gateway.

 

Environment

VMware NSX

Cause

Overlap subnet between local site and remote IPSec VPN site causing VPN traffic route to local site.
This creates conflict in routing causing connectivity loss

Resolution

Remove the overlapping subnet from T1 gateway.