Migrating NSX edge VM's to new blades [ esxi hosts] in vCenter causes complete network disruption.

Products

• VMware NSX

Issue/Introduction

•  When edge vm's are migrated from old ESXi Transport Node to new ESXi Transport Node the TEP (Tunnel Endpoint) status and Edge node TEP status is in UP state, but the reachability to NSX VM's from outside network fails.

 

Environment

VMware NSX

Cause

• TEP connectivity between host to edge and vice verse is between two different network, so the routing is performed on the physical L3 interface.
• Network Configuration: Tier-0 Routing, BGP, packet capture, NSX trace-flow to isolate the issue.

Resolution

•  We performed packet captures on the NSX edge node and esxi host for North-South traffic  to isolate the issue -- Troubleshooting NSX using Packet Captures
•  The issue was on the physical network and found there is a routing discrepancy and traffic was dropping while initiating from the source VLAN.
•  BGP route-map value was not configured correctly on the vendor side, updating the correct route-map weight value resolved the issue.