Right. But what do the routing tables look like on the other machines on the 172.20.1/24 network? I'm guessing that there's some sort of problem there, now, that's cropped up due to the other changes that you mad in the network.

And, just to reiterate, everything's working right now except for the original network that worked right before cannot connect to the internet or to the new network, right? Can they ping each other and/or the interfaces on the two routing boxes that are on their network?