VMs getting disconnected from Networks after vmotion. Failed to create filter, too many filters

Products

• VMware NSX

Issue/Introduction

Symptoms:

• VMs show disconnected from their network. Unable to reconnect them until affected VM (or other VMs) are migrated to another ESXi host.
• ESXi host version is 6.5 or older.

On vmkernel.log of the host containing the affected VM, the below error can be seen:

2021-07-23T08:33:53.212Z cpu62:13461971)Net: 2325: connected guestVM1.eth2 eth2 to vDS, portID 0x30043b9
2021-07-23T08:33:53.212Z cpu62:13461971)Net: 3018: associated dvPort 11590 with portID 0x30043b9
2021-07-23T08:33:53.213Z cpu62:13461971)DVFilter: 3962: Failed to create filter, too many filters
2021-07-23T08:33:53.213Z cpu62:13461971)DVFilter: 5713: Failed to add filter vmware-sfw on vNic 2 slot 2: Out of resources
2021-07-23T08:33:53.213Z cpu62:13461971)WARNING: Net: 3064: DVFilterActivateCommon failed for port 0x30043b9: Failure
2021-07-23T08:33:53.214Z cpu62:13461971)Net: 3560: dissociate dvPort 11590 from port 0x30043b9
2021-07-23T08:33:53.214Z cpu62:13461971)Net: 3566: disconnected client from port 0x30043b9

Environment

VMware NSX Data Center for vSphere 6.4.x

Cause

The limit of DVfilters per host is 1024 by default on ESXi 6.5 and earlier versions.
Each VM's vnic can may utilize 2-3 dvfilters / slots, depending on features in use, such as NSX Distributed Firewall.

Resolution

In ESXi 6.7 and above the default maximum number of filters supported per host has been increased to 8000.

Workaround:
As workaround you may increase this number from 1024 to 2048 running the command below on ESXi host.

• esxcli system module parameters set -p dvfiltersMaxFilters=2048 -m dvfilter
• Reboot ESXi host in order to apply the new maximum.

Additional Information

Impact/Risks: