Say everyone uses rfc1918 space, and you want a fairly good guarantee of IP uniqueness. What options do you have?

You can:

  1. Buy IP space from ARIN
  2. Find sneaky address space unlikely to be used and declare it yours.

Funny to see which is labeled as a test network. It seems that people mentioned that IP space so many times in internetworking examples that no one can use it now. You'd connect up your network, and you'd get a slew of random inadvertently escaped packets.

Which looks like (held/reserved by IANA); imagine having to deal with either of those packet flows?

rfc3330 talks about the address space. -- -- -- - This block is assigned as "TEST-NET" for use in documentation and example code. It is often used in conjunction with domain names or in vendor and protocol documentation. Addresses within this block should not appear on the public Internet. -- -- -- I just happened across this the other day when setting up a shorewall box. -- Nathan