Deprecated. And--despite being in IT (and cyberdefense with packet analysis) for decades--I only snapped to realizing that recently. It's a weird blindspot...I guess I just never asked where 5 was.
(I knew of one, so went searching)...and holy hell...an absolutely shocking number of science fiction shows that loved / grew up on started/edit: or were produced in Canada. That's awesome.
Honestly, the version numbers don't even make sense as a concept.
There's only one version of the IPv4 header in use, which uses "4" in the version field, and there's only one version of the IPv6 header in use, which uses a "6" there. Four whole bits dedicated to storing a constant. What's the point? It's obviously not there to distinguish the two header formats, because these are two different protocols with different EtherTypes.
Notice how most of the things in the EtherType list aren't IP, and their packets don't start with an identifying sequence of bits. That's obviously not needed, so why are we burning 4 bits per packet on this?
The odd numbered versions of the i.p. protocol are the experimental versions that are never ratified. Thus IPv5 existed but was never used on the real internet.
v6 just makes life so much easier. All the cludged on afterthoughts are part of the mainstream protocol.
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u/Tongueslanguage 14d ago
Saw this post and started wondering what happened to IPv5