When connecting two different VLAN Trunk Protocol domains together via an ISL trunk, the switches fail to form the trunk automatically. What is the likely cause?
Using the debug mpls l2transport signaling message command, what kind of attachment is connected?
00:19:51: AToM LDP [172.168.1.102]: Sending label withdraw msg vc type 4, cbit 1, vc id 100, group id 0, vc label 20, status 0, mtu 1500
00:19:51: AToM LDP [172.168.1.102]: Received label release msg, id 78 vc type 4, cbit 1, vc id 100, group id 0, vc label 20, status 0, mtu 0