Private use of non-RFC1918 IP space

Tico tico-nanog at
Mon Feb 2 18:35:29 UTC 2009

Andre Sencioles Vitorio Oliveira wrote:
> What about this?
> Genius from company A chooses public IP block A.
> Genius from company B chooses public IP block A.
> Genius collision detected...
That's pretty nasty.
However this should be able to mitigate some of the ugly scenarios 
brought up in this thread:

Mind you, proper due-diligence could avoid most of these, and/or 
companies not all choosing to use the default 192.168.{0,1}.0/24 that 
their SOHO Netgear/Linksys router ships configured with.

> On Feb 2, 2009, at 4:06 PM, sthaug at wrote:
>> 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, and then merging. Conflict ensues, renumbering
>> or NATs required in order to connect the networks.
>> Steinar Haug, Nethelp consulting, sthaug at
> Andre Sencioles Vitorio Oliveira
> asenci at

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