I have two Catalyst 2950 switches that I am trying to link together, but when I run a cable between the two (doesn't matter which port)it produces a wierd fast flashing light on the ports and stops all traffic on the switches. As soon as I remove the cable, traffic resumes as normal. Any ideas?
no spanning-tree vlan 1 <--- This is the issue. No spanning tree and two connections between switches equals a network loop. Unplug one cable, enable spanning tree and plug the second cable back in. If you do a sh spanning-tree, one of the ports will be forwarding and one of the ports will be blocking. This is spanning-tree in action (stopping that network loop). Delete the etherchannel configuration on port 22 and re-configure it for ports 23 and 24. Spanning-tree no longer needs block any ports, becasue they are now one logical port.