How does that help? If you are renumbering due to a merger, couldn't you just agree on separate private space just as easily?
It would ensure that you could get the networks to communicate, without IP address conflicts, *before* you started any renumbering.
Can you expand? I assume that everyone understand VPNs so connecting over the Internet is not the issue. If you pick a public IP block you still have to agree on that block. How is using a public block different than agreeing on a private one?
Company A uses public IP block A internally. Company B uses public IP block B internally. Company A and B later merge, and connect their networks. No conflict, no renumbering needed (at least not right away). Compare this with company A and B both using overlapping part of for instance 192.168.0.0/16, and then merging. Conflict ensues, renumbering or NATs required in order to connect the networks. Steinar Haug, Nethelp consulting, sthaug@nethelp.no