ESXi host with NSX distributed load balancer (DLB) and distributed firewall (DFW) configured crashes with a purple diagnostic screen (PSOD)

Products

• VMware NSX
• VMware vDefend Firewall
• VMware vSphere ESXi

Issue/Introduction

An ESXi host crashes with a purple diagnostic screen (PSOD) displaying information similar to the following:

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Environment

• VMware vSphere ESXi 7.x/8.x
• VMware vSphere ESX 9.x
• VMware NSX 4.x/9.0.
• VMware vDefend Firewall 4.x/9.0
• Distributed load balancer (DLB) and distributed firewall (DFW) are configured in NSX
• A drop rule is configured in DFW rule list
• The DLB or the DFW are reconfigured

Cause

A race condition can occur in the handling of DLB sessions that may lead to a host PSOD.

Resolution

This issue is resolved in the following NSX versions:

• VMware NSX 4.2.2.2
• VMware NSX 4.2.3.1
• VMware NSX 9.0.1

Workaround: Remove the drop DFW rule or modify it to be an allow rule.