VMs connected to NSX-T port groups on VDS lose network connectivity

Products

• VMware NSX-T Data Center

Issue/Introduction

• NSX-T is configured to use VDS with VMs connected on it.
• VMs on an ESXi lose network connectivity at the same time.
• The following logs indicates the impacted VMs are detached from logical ports.

nsx-syslog.log

2021-07-08T16:09:57Z nsx-opsagent[2110022]: NSX 2110022 - [nsx@6876 comp="nsx-esx" subcomp="opsagent" s2comp="nsxa" tid="2110554" level="INFO"] [DoVifPortOperation] request=[opId:[sync-detach-41] op:[SYNC_DETACH_PORT(1002)] vif:[########-####-####-####-##########d8] ls:[########-####-####-####-##########fb] vmx:[/vmfs/volumes/########-########-####-##########58/VM/VM.vmx] lp:[########-####-####-####-##########ec]]
 

Note: The preceding log excerpts are only examples. Date, time, and environmental variables may vary depending on your environment.

• The impacted ports are marked as blocked.

#net-dvs -l | grep -E "port |port.block|volatile.status"
port ########-####-####-####-##########71:
                com.vmware.common.port.block = true , propType = POLICY
                com.vmware.common.port.volatile.status = inUse linkUp blocked portID=67108871 Port blocked by admin propType = RUNTIME

Environment

VMware NSX-T Data Center
VMware NSX

Cause

NSX-T periodically performs resync operation so that stale logical ports are cleaned up.
However due to a known issue the resync script does not correctly identify VMs that are connected to NSX port groups and VMs are wrongly detached from logical ports.

NOTE: NVDS is not affected by the issue.

Resolution

This is know issue affecting NSX-T 3.0.3 / 3.0.3.1 and is resolved in NSX-T 3.1.2.x / 3.2.x and higher.

Workaround:
1. Connect the affected VM's NIC to another port group and then connect back to the original port groups.
2. Use NVDS in place of VDS to avoid this issue.

Additional Information

Impact/Risks:
VMs lose network connectivity if they are connected to NSX-T port groups on vDS.