John Kristoff wrote: >> IP protocol version 5 is already defined and in usefor RFC1190, and >> that use would have to be deprecatedfirst. Picking 7 is easier; for a >> long time someoneon this list was pushing an idea of IPv8... and IPv9. > > I believe the IPv8 you are referring to was hardly a serious proposal. > Regardless, 7, 8 and 9 were reserved for TP/IX, PIP and TUBA > respectively. When IPv6 WG decided to use a different EtherType from that of IPv4, the WG decided to keep the version number field of IPv6, even though the field is unnecessary, only to keep calling IPv6 IPv6. That is, for new IPs, we have 16 bit space managed by IEEE, not IANA. Masataka Ohta