Need an opinion. This is the setup:
Two sites (200 meters apart) with a router installed in each site. Each router as it's own WAN link belonging to the same network.
Each site has a 3550 which is connected to the router. Between the 3550, there's a fibre link connecting each other for redudancy purpose.
If the fibre breaks, i want both sites to be functional. Which setup would be the preferred choice : HSRP or GLBP.
unfortunately in that case of fiber broken between the two switches you have 50% probability that return packet will go to the right side:
some hosts can be lucky and see their return traffic, but others will be able to send traffic but not to receive it
from the core point of view both WAN links are good to reach hosts in the client Vlan IP subnets it is impossible to say what host is reachable via R1 and what are behind R2.
However, you can double the fiber link or even use three different links between switches (with or without using an etherchannel) in order to reduce the probabilities of this scenario.
Hope to help