I created an etherchannel on two ports (2960 switch) and placed them into an etherchannel. Did the same on the other switch Cisco 3020 blade chassis switch. Without connecting any cables the 2960 had done an up/down sequence as though a cable had been connected and yet this had not been done. Can someone try and help with what could be the technical explanation of this interesting phenomena. the etherchannel was a trunk and the ports were sitting in vlan 200 and this vlan was also configured as the native vlan for the trunk.
Please, please help - any comment is appreciated.