Client IP Conflict Detected

[Shadius]

Hi all,

I'm getting this client IP conflict detected message from my MX250 appliance. There are multiple clients with the same MAC address on the network. It looks as if the MAC address hops around to different clients. I'm not sure how that is happening. I'm not even sure if this makes any sense.

Can anyone help in trying to figure this out, please? 

I don't even know where to start.

[PhilipDAth]

There are multiple clients with the same IP address - or the same mac address?

[Shadius]

Multiple clients with the same MAC address. 

[Shadius]

We have a Domain Controller with a static IP address and the Meraki Event Log is showing that every hour or so the MAC address is XYZ then another hour or so it's ZYX.

There's teaming on the two NICs on the Domain Controller.

[PhilipDAth]

It is probably related to your teaming configuration.  You probably have it set to use "Switch Independent", which causes the Windows server to keep flipping between the MAC address of the NICs.

If you have a switch that supports LACP then you can configure that which will stop the issue.

[Shadius]

The teaming mode is set to Smart Load Balancing With Failover.

How can I check if the switches have LACP already configured or not?

[Happiman]

It could be a WIFI clients moving around your building. Switches remember the IP Address and its MAC, then it gets the new IP address, before your switch flushes the MAC.

[Shadius]

The Wi-Fi is on a different network.