Hello everybody

I am new in Mikrotik world and I have a small question,
I have 2 rb2011 devices in remote places with hotsopt configured in both, they both use radius server installed in one of them.
I am planing to install a new device also in a remote area, hotsopt also and I want it to use the same radius server.

Now I need to configure a backup radius server to handle the request in case the main one goes down, is it possible and if so how to do it, and how to replicate the DB between the two servers??

Thanks in advance