Cisco switch mac flapping error logs

  • 1 July 2019
  • 1 reply

dear team,

In my cisco switch getting log like macflap, what is it means ??

*Mar 3 16:07:53.242 GMT: %SW_MATM-4-MACFLAP_NOTIF: Host a896.752b.8e60 in vlan 17 is flapping between port Gi2/0/9 and port Gi2/0/24

1 reply

Userlevel 2
MAC Flapping happens when the same mac address is seen on 2 ports and is learned on one port and then learned on another, and then again on the first port, and so on. This usually indicates a loop or other misconfiguration or wiring issue on your network. Please check the devices connected on those ports (Gi2/0/9 and Gi2/0/24) and follow the path until you can determine the cause for the loop or other reason that MAC address is being seen on 2 ports.