External services aren't reachable post V2T migration

Products

• VMware NSX

Issue/Introduction

• After performing a migration from NSX-V to NSX-T, workload VMs are unable to reach external web pages

• Services aren't reachable post migration

• ICMP tests from workload VM to external web server shows successful reachability

• Trace routes from source to destination also show successful

• Attempting to load external web pages from the VM workloads times out and/or fails

• NSX Host and Edge TEP networks are on different subnets/VLANs

• vmkping tests from NSX Host to NSX Edge fail with anything over an MTU of 1472 (In this scenario, jumbo frames are being used):

  • From NSX Host CLI: vmkping ++netstack=vxlan -I vmk10 -s 8972 -d <dst-edge-TEP>

Environment

VMware NSX

Cause

MTU on the default gateway interfaces of the Host TEP network and Edge TEP network are not configured properly

Resolution

Increase the MTU of the gateway interfaces that are routing the TEP traffic between NSX Host Transport Nodes and NSX Edge Transport Nodes

Additional Information

Related KBs:

Addressing Common NSX Underlying Infrastructure Connectivity Issues

Troubleshooting NSX Network Connectivity Issues

VMs experiencing packet drops on internal network with jumbo frames (MTU greater than 1500)

Troubleshooting MTU issues and fragmentation in NSX fabric