Our business currently subscribes to a DSL internet connection. We're moving away from this and in fact will have two 3Mbps dedicated fiber connections run into our operations center in the coming weeks. The first fiber connection will be ready in 2 weeks, the second in 2 months.
My question is with regards to DNS records, specifically in publishing multiple DNS records that point to the same address. When the first fiber connection becomes available I will want to have our domain (www.example.com) point to both it and the old dsl service. I will be using a multi-wan router to handle both connections. When the second fiber connection is installed I will essentially do the same configuration as before, cutting the dsl conn out of the loop. I'm fairly new to DNS and am concerned as to how I might achieve this.
Just add multiple IN A records, they will be randomly served by your DNS server.
See Round robin DNS on Wikipedia