Mutiple Authentication on Interface Causing Mac-Flap

[Ryan10]

Hi Cisco Engineers,

Have you experience a multiple authentication on one interface but there's no hub/switch connected to it. Only once PC connected to the interface but many Mac Addresses trying to authenticate (using 802.1x). As I traced the Mac Addresses, they are legit PC but connected to the ports of the other switch. It seems like Mac Spoofing.

I have researched what cause the issue, and some forums tells it's about Wake On LAN or Wake Up Proxy. But as I checked. there's no Wake On LAN or Wake Up Proxy configured on PCs/SCCM.

Please see the screenshots. Thank you.

[crathnaswamy]

I have the same issue in 2024/25 after implementing NAC. ISE performing NAC on user ports, cauing MAC flapping. Any resolution or guidelines?

[MHM Cisco World]

Please make new post 

Thanks alot 

MHM