Hi There,
I hope everyone had a good rest and is ready to tackle 2017 
I need some advice regarding an issue I have with one of my customers. The customer has two sites (Main and DR) which is essentially on the same layer 2 network , meaning both sites shares the same IP network and are essentially one LAN but the switches are connected with Metro fiber over a 30km distance. Now this all works well but customer also have a radio between the two sites which they want to use as an automatic failover. Usually I’ll just use normal STP but the upstream provider is blocking the bpdu packets and is either unwilling to unblock them or doesn’t have a clue howto .
Anyway , I’m in the process of looking for an alternative and was wondering whether it would be possible to build something with the Microtik / Routerboard to accomplish this and was hoping that it might support some other failover protocols other then normal STP. The setup is rather simple. The main network plugs into a switch which connects to the DR site via a metro fiber connection. So basically a 30km fiber link connecting two switches with a Wireless bridge as failover.
Thanks in advance,
EoIP over both links, or maybe QinQ and STP in the inner VLAN?
Try to use “horizon” feature in bridge ports.
Thanks for the advice . I’ve been considering the “CRS125-24G-1S-IN” , would this be sufficient ?
Also , after reading the documentation on the horizon feature is my understanding correct that the protocol bonds your primary and secondary paths into one ? So basically packets will get transmitted across both the Fiber and wireless link simultaneously ? If this is the case then it might be a little problematic since the Wireless link isn’t very reliable and should only be used in case of an emergency. Is it possible to tell the switch to only activate the redundant path when the primary drops ?
Thanks again for all the info.
http://wiki.mikrotik.com/wiki/Manual:CRS_features#Cloud_Router_Switch_models
be aware that if you will use vlans and there will be routing between them, that can consume much CPU of your main router.
(Yes, forget about wirespeed: http://forum.mikrotik.com/t/intervlan-speed-problem-with-rb2011-and-crs125/96138/3 ) It’s better to choose model with Access Control List.
Thanks for the info.
I don’t think there will be allot or even any routing involved since the main and DR sites will essentially be on the same network connecting the two switches with a Fiber as the main path and a Wireless link as a redundant path. Both the main and DR site shares the same IP network : 192.168.0.0/24 … The link also only have around 30Mbp/s capacity .
My major goal is basically to setup automatic failover between the Wireless and Metro fiber link since I’m unable to use STP through the metro link. They’re also either incapable or unwilling to allow me to use QinQ for an inner Vlan 
thanks again,.