Hello NANOG'ers, This is a question that popped into my mind recently. So far my google-fu has not turned up anything of use. Imagine a company that has an RIR-assigned IPv4/23, and has it subnetted into a pair of /24's so that they can have replicated datacenters in two different geographical locations each running its own BGP infrastructure (using the same ASN). As far as I can see, this is all fine and good assuming that these two sites are in the same RIR's domain. Is it possible/allowable to move one of these datacenters to a different geographical region with a different RIR and keep using the same two subnets, or will a new /24 need to be requested from the new RIR? If there's a book or reference that answers this question, please let me know - I'm willing to do as much research on my own as I can. Thanks!