Diagnose NSX-T T0 tunnel down

Products

• VMware NSX

Issue/Introduction

NSX-T shows tunnel down for T0

Environment

NSX-T 4.x

Cause

T0 tunnel shows down in NSX

Resolution

• Refer to Broadcom doc,  for configuring T0
• Determine the IP used for the T0 overlay
• Access SSH to the edge node the T0 is on
• Using  traceroute very the IP used for the T0 overlay has connectivity
  
  • for example traceroute 127.0.0.1 should return the routes to that IP
• If traceroute fails to provide routing to the overlay IP.  
  • Confirm vCenter and ESXi networking for the edge node
    • ensure the edge NICs are configured correctly to access the physical network
  • Confirm the physical network is not blocking access from the ESXI host to the IP entered for the overlay

If further assistance is needed please contact Broadcom Support