james.cutler@consultant.com wrote:
I have yet to find an economical way to manage a business merger involving two large rfc1918 networks where end to end peering is required and which partially or fully overlap.
As you mention "overlap", you should mean business merger implies network and office merger, which causes relocation of a office, which, in general, requires provider change and renumbering of globally unique addresses, unless you own /24.
Ignoring short-sighted financial management views, the best long term solution is globally unique IPv6 addressing wherever possible.
See above. Or, if you mean network merger remotely with VPN, small number of hosts requiring E2E transparency may be renumbered, but it is not so painful. Masataka Ohta