Freeradius + Mikrotik (Step 2)

On FR box

vi /etc/freeradius/3.0/clients.conf

add following

client mikrotik {
ipaddr = ip_router_mikrotik
secret = secret_to_connect
nas_type = other
}

ON MT, enable radius, input workwith services (hotpost,ppp,or so), input FR ip address, with secret.

Done.