Good to know that but how exactly, Is it multi homing?
This can be done in variety of ways.
For example one way could be that you insert both WAN links in single switch, and then connect this Switch with mikrotik WAN. In Mikrotik , you can add secondary IP address on the WAN interface, means WAN interface will have ip addresses for both wan links. now create secondary route for your second link. Then simply apply fail over scenarios as per your need, for example either via scripting, or using virtual hops, or using netwatch to initiate scripts if any links goes which can also email you the info too
, I wrote some rough notes about fail over on my blog too. Try
http://aacable.wordpress.com/2013/04/12 ... r-scripts/