Duplicate IP address for DLR or UDLR reported by NSX manager or network monitoring solution in NSX 6.4.x

Products

• VMware NSX

Issue/Introduction

Symptoms:
Duplicate IP detected for DLR Control VM. The alert can be seen in NSX Manager Events, vsm logs, vRNI or similar monitoring solution. 

vsm.log has INFO Alerts similar to :

INFO SimpleAsyncTaskExecutor-1 EventServiceImpl:128 - - [nsxv@6876 comp="nsx-manager" subcomp="manager"] [SystemEvent] Time:'Fri Aug 31 02:34:35.000 CEST 2018', Severity:'Critical', Event Source:'edge-<vmname>', Code:'30157', Event Message:'NSX Edge edge-e3a0f320-088c-40f1-9682-8e####### detected duplicate IP #.#.#.# with macAddress null', Module:'vShield Edge Appliance', Universal Object:'false'

Environment

VMware NSX for vSphere 6.4.x

Cause

When an edge is a DLR, the external IP is shared between the VDR and the Edge itself. DaD (Duplicate Address Detection) module tests any vNic that has an IP address configured, and finds the IP on both the VDR and Edge interface.

Resolution

Issue is resolved in NSX 6.4.2  - Fixed Issue 2139594

https://docs.vmware.com/en/VMware-NSX-for-vSphere/6.4/rn/releasenotes_nsx_vsphere_642.html

Workaround:
There is no work around for this behavior

Additional Information

Impact/Risks:
No impact, issue is cosmetic