Could someone explain how an entire VLAN is flapping... ? I didn't even learn about flapping in my CCNA.

Host 58b1.xxxx.xxxx in vlan 101 is flapping between port Fa0/1 and port Fa0/3. I just don't get it.

Both Trunk ports. I get what flapping is on a single port but what does it mean when multiple ports are flapping over a vlan?