Failover link between two GS728TPs

[jasonh148]

I have two GS728 switches in different buildings. There are two links between the buildings; a point-to-point wireless and a fibre. I would like to have both connected to the switches and have the switches automatically use the fibre as primary path to each other, and PtP wireless as a secondary/failover.

What is the best way to set this up? I've seen it done before using STP priority. But from reading through documentaiton, LACP might be best?

If LACP, I think I understand the concept - put the two ports in the same channel, and assign one a priority over the other? I've never setup LACP so wonddering if there's any pointers or something I can read that gives a better understanding than the switch manual - e.g. do I configure this on both switches or just one? Does anything at all need to be done on the other switch (e.g. disable STP?)

[schumaku]

Afraid, LACP is to aggregate two or more links with the same link sped and latency only.

STP, much more RSTP, is your friend for such a config.

[jasonh148]

Good to know, thanks!

For RSTP, how do I tell it which port is primary/secondary? CST Configuration settings, set the port priority?

[schumaku]

In STP and RSTP, it's about the interface path cost. The cost prioritizes routing to the destination. The lower the cost, the higher the priority.