Working with a client that has a 3750 connected to a Metro-E to link up to their remote branches. The 3750 has a L3 port interface connecting to the Metro-E. Their provider is pulling a 2nd fiber (from a separate CO, different fiber path) to give them additional WAN redundancy. I see that they have two options to connect:
1) Pull into another port on the same 3750 stack (this is their Core). Move the L3 ip address to an SVI, put both ports in the same VLAN and let Spanning tree block one of them. Simple, fairly quick failover ...
2) Pull the 2nd link into another stack, add L3 SVI interfaces to the 2nd stack for all the internal VLANs and a L3 switchport for the Metro-E. Then use HSRP. Less simple (have to create a second core, add HSRP, ...) but keeps STP out of the picture.
Any thoughts, suggestions appreciated.