NSX EDGE dropping packets when virtual machines are running on the same ESXi host and are on the same port group

Products

• VMware NSX

Issue/Introduction

Symptoms:

• NSX Edge is dropping packets when virtual machines are on the same ESXi host
• No information found in logs
• The esxtop command shows the NSX Edge had a high SWPWT value similar to:

  

Environment

VMware NSX for vSphere 6.4.x

Cause

This issue occurs when the NSX Edge is created from vCloud Director and modified in NSX Manager. When the NSX Edge was created as "Compact" from vCloud Director, it only provided the NSX Edge with 256MB memory.

When the NSX Edge was upgraded from the NSX side, the setting still remained.

During troubleshooting, a check was done on the the .vmx file on the NSX Edge and found this entry:

sched.mem.max = "256"

This would mean even though the edge had 8 GB memory configured, edge would only get 256MB.

Resolution

To resolve this issue, change the size of the NSX Edge from vCloud Director. This changes the configuration of the NSX Edge and adds 1GB memory as the maximum limit.