NSX Edge Nodes Fail to Pass Traffic After Power Outage or Infrastructure Restart

Products

• VMware NSX

Issue/Introduction

Following a full environment power cycle or cold boot of the infrastructure, VMs residing on NSX segments lose all external network connectivity. Although NSX Edge nodes and NSX Managers appear to be powered on and operational, no traffic passes through the Edge nodes to the physical core switches.

Observed Behavior:

• NSX Manager UI shows Transport Nodes (Hosts and Edges) as Up and Running.
• BGP neighbor status may show as Up, but Traceflow indicates "No routes" for the data path.
• Traffic fails to traverse the Edge nodes despite administrative status appearing normal.

Environment

VMware NSX

Cause

The issue is caused by a timing and synchronization mismatch during the environment's startup sequence. The NSX Edge VMs initialized and attempted to establish their network stack before the underlying physical network infrastructure (core switches and BGP neighbors) was fully converged and ready to process traffic. This prevented the Edge routing tables and ARP/MAC tables from correctly refreshing or learning the necessary routes.

Resolution

Workaround:

Once you've confirmed that the NSX Edge nodes and Managers are back online, you may need to kickstart the connectivity. Go into the vCenter UI, find the Edge VM settings, and manually disconnect the network adapters. Save those settings, then go back in and re-enable them. This "bounces" the connection and should restore traffic flow.