Using Region-X assigned IP space in Region-Y?

Owen DeLong owen at
Sun Mar 27 19:27:10 CDT 2011

On Mar 27, 2011, at 7:58 AM, Mark Leonard wrote:

> 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.
It actually doesn't matter where they are located, but, it is a lot cleaner to use
different ASNs as the two networks have different routing policies.

> 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?
Yes, not a problem.

> 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!

As a general rule, you can get all your space from the RIR that serves
the region where your company has its headquarters, or, you can get
space from any region where you have equipment deployed.


More information about the NANOG mailing list