Re: A different solution
The odd numbered versions for IP standards are the experimental or working drafts. So IPv4 was preceeded by someone playing around in a standard called IPv3, IPv6 had IPv5 before it and IPv7 was being kicked about years ago as far as I know.
Nope. IPv4 was the first release, the name is a retronym coming from the 'type of packet' field to allow multi-protocol links atop DLLs that don't provide an equivalent capability natively (ISTR HDLC is one but don't quote me on that). The first IP got assigned a code of 4, by the time its successor arrived 5 had been allocated so it got 6. The 'version' numbers simply reflect those codings.