I've been doing a lot of reading on the forums and I can't seem to find exactly what I'm looking for.
We have a few situations where we have a single router that we want to make as highly available as possible. Due to connection limitations each device has the requirement that it is the only device that can have the outgoing connection. (It can be many different things.) We'll assume all the devices have two onboard ethernet ports.
Given those requirements it seems to me the best bet would be to utilize both ports and have them connected to different switches. The best way that I can see would be an etherchannel but that means the switches would have to be stacked or connected to a chassis based switch and that is not an option.
The second best option to me seems to be bridging the interfaces and let spanning tree do the work. I've seen posts that say this should not be used moving forward but to me it seems much nicer than having a bunch of very small networks and doing it at Layer 3.
I'm looking for some thoughts on this. If bridging shouldn't be used then why shouldn't it?