Can someone give me a quick high level overview of BGP, as it relates to Internet routing tables, and looking glass sites?
Specifically, my small site will be moving ISPs, from MCI to AT&T. Our /20 network is being advertised by MCI right now. The routers we manage have nothing to do with it, we just static route to an MCI router, that handles the BGP. But it's our address space (asigned to us), not MCI. So when we move to AT&T, they will start to advertise that address space.
The ISPs assure us that they will work together to handle the routing transition. Which is fine. But I'd like to at least understand a little bit about how it works, and how I can verify (using Looking Glass sites I think?) who is advertising it?