Just picked up a client with a bonded T1 through Time Warner and have run into a configuration that I didn't know was possible, just wanted to find out why or how this is possible.
Firewall is a Sonicwall Pro 2040.
Their primary external IP is (changed) 126.96.36.199 with a /30 subnet, with an internal NAT 10.24.1.0/24.
There are also one-to-one NAT entries for several servers. Their external IPs are 188.8.131.52-151. And the entries work.
Should this be possible? Is this something that the ISP has to set up to be possible? Is there a good overview of one-to-one NAT that I could read to understand what's going on?