replying inline since i'm lazy and want to quote your post rather than having to copy it across in the other edit window.
i realize my initial post wasn't exactly helpful.
at any rate:
said by wirelessdog:Seems like STP would be an easy way for auto failover but can I specify the primary link if I do that?
stp is all about cost to the root bridge. you need to make sure you set the root of your layer-2 network appropriately through vlan priority or whatever. make sure that your stp instance(s) are mapped such that the "center" of your network -- whatever you determine that to be -- is static -- rather than through the general stp election process.
once you have your root bridge mapped -- everything else becomes a matter of "lowest cost to the root". in this way -- you can make sure that the "lowest cost" path is selected as the root port (i.e. the port that is facing the root bridge). you can let stp automagically calculate costs -- or you can set the cost manually.
said by wirelessdog:I'm also open to load balancing if there is a way to do that on a bridge.
layer-2 is a single path active. you can get fancy with setting different costs per path if your stp variant supports multiple spanning-tree instances within a single domain -- but if you only have a single instance for all vlans -- then you're effed. there are technologies that are out there that allow for "trickery" -- but in a wan network -- you don't want to employ them (if they are even available on your hardware). to get true "equal cost multipathing" (ecmp) -- you'll need to move to a layer-3 network. as a side note -- the only routing protocol that supports "unequal cost multipathing" is cisco's eigrp protocol -- wherein you set variance across your different paths and the traffic weight is based on the variance ratios. rarely do you see this being done -- as well -- its more work than its worth. often if something like this is truly needed -- some sort of 'policy based routing' (cisco) or 'filter based forwarding' (juniper) is employed. cisco has their own take on this called "performance routing" (pfr) that you can use given criteria, etc into determining best path -- but given that you're not running cisco kit everywhere -- you can't employ such a solution.
q.