IPv6 Doesn't Have As Much Address Space As You Think

[derekivey]

Just saw this article: http://jhw.dreamwidth.org/1650.html. I thought "this guy is crazy" before I read it. It kind of makes sense, but I can't imagine ever running out of IPv6 IPs. Who knows though...

Thoughts?

[antillie]

Cryptographically encoding host identity information inside an IPv6 addresses seems like a waste of time to me when IPSec can already achieve cryptographically secure origin authentication. And who cares if a few hundred /32 prefixes get reserved for oddball things like Teredo and NAT64. There are ~4.29 billion /32 prefixes available.

If you really want to embed stuff in your IPv6 packets you can just use IPv6 header extensions, that's what they are for anyway. There is no need to try and use the address itself to send information. That's what the packet headers and payload are for.

[jschweitzer]

i read this article this morning too.

the guy is trying to quantify the IPv6 address space in a way that the human brain can understand, but it's not possible.

even w/ a /64, there's 18 quintillion unique subnets to "hand out."  There is just no way for a human to understand 18 quintillion.

also, this ORCHID protocol is to be used as a temporary allocation by IETF... it's temporary.  it's an experiment.

the guy is just fearmongering.

[derekivey]

i read this article this morning too.

the guy is trying to quantify the IPv6 address space in a way that the human brain can understand, but it's not possible.

even w/ a /64, there's 18 quintillion unique subnets to "hand out."  There is just no way for a human to understand 18 quintillion.

also, this ORCHID protocol is to be used as a temporary allocation by IETF... it's temporary.  it's an experiment.

the guy is just fearmongering.

That's what I thought. Thanks!

[Mierdin]

It made my day to see that the comment by Owen. Poor allocation practices are obviously things to be avoided with address spaces of any scale.

That comment was extremely educational, though.

[sttun]

even w/ a /64, there's 18 quintillion unique subnets to "hand out." 

Ehm, No a /64 is just one subnet as the last 64 bits are interface id, so if you need more than one subnet (at least when using starless auto config (ie RA) your ISP will need to assign a prefix length <64 to you.
As to what prefix length you will get, thet is upto your ISP using (according to IANAs recommendations) a maximum of 64 bits.