Nat and multiple servers. . .

OK I have two ISP’s one is a business class cable and the other is a fractional T1 (each of these has 12 outside ips)

I am using a mikrotik router board with 3 nics

i have each isp on one and the internal switch on the other

i am currently using masquerading and all traffic is going out the cable connection on a single ip address.

should the cable connection fail the t1 picks up the the slack.

here is where it gets interesting i need to bring over our web and dns servers ( currently co-located)

i will need to give these different servers outside ip addresses

what is the easiest way of going about this?

maybe dynamic DNS can help you, so, if one fails, your dns changes to 2nd ISP ip address