The problem I saw was SP-BSwitch1 port facing SP-ASwitch1 goes into error disable state due to L2TP gurad.
The reason as defined by L2TP gurad reference is as follows
"The interface goes to errdisabled state, If an encapsulated PDU (with the proprietary destination MAC address) is received from a tunnel port or access port with Layer 2 tunneling enabled, the tunnel port is shut down to prevent loops"
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...