I must connect two Cisco 7606 with two Cisco Catalyst 4506 at level 2 only. The final topology is a square. The Catalyst 4506 are connected to three routers in dual-homing and have a Port-Channel between them. When I connect the 4506 to the 7606 I have to transport a VLAN only so the trunk is not needed. I'd like to avoid the spanning tree timer calculation when I plug the cable because the router are in a live network and I'm scared to lost traffic.
I thought to configure the port connected to the router with span tree portfast and remove the vlan from the trunk back-to-back. Is that a good idea or exist other better solutions?