We have a stack switch (two phsical ones) connected to two NICs with one server. We setup NICteaming on server side. We also configure Etherchannel (PAGP)on cisco side. Since we configured two NICs as active/avtive, I think the network connection is ok even though we disable one NIC. But the result is negative.So I tried to disable etherchannel on switch side, the connection could move back active one when I tired to disable one.But I got the following logs: "Host 0050.xxxx.yyyy in vlan zzz is flapping between port Gi2/0/10 and port Gi1/0/30", I am not sure if it is normal behaviour. I was pretty sure it is not related to SPT issue. Please give me two cents. Thanks a lot!