Company A uses public IP block A internally. Company B uses public IP
OK, so we start out with a bad network design then.
No. We start with blocks A and B which are both properly allocated by the relevant addressing authorities.
block B internally. Company A and B later merge, and connect their networks. No conflict, no renumbering needed (at least not right away).
Maybe. What if they both happened to choose 1.2.3.4/8? Is this just a matter of decreasing the odds of a conflict? It still seems like bad network management to me.
My assumption throughout this whole discussion, which clearly has not been understood, is that the public IP block used internally is a properly allocated by the relevant addressing authority. That is, for me, the whole point of using public addresses to guarantee uniqueness. Steinar Haug, Nethelp consulting, sthaug@nethelp.no