4 ms·
IPv6 has a 2^128 address pool. edit: theoretically, we'll only ever use a fraction of that, both by design and because that's a huge number
by jrimbault 9y ago
IPv6 has a 2^128 address pool.
edit: theoretically, we'll only ever use a fraction of that, both by design and because that's a huge number
- ghshephard 9y agoWell, because there is no equivalent to CIDR with IPv6, what you really need to focus on is the 2^64 networks available. Still a big number.
- jrimbault 9y agoThat's what I meant in my edit :)
- oarsinsync 9y agoAnd yet I still have /127, /126, /120 and /112 IPv6 subnets running on my network. Just because the IETF says SLAAC or bust doesn't mean it's true.
- ghshephard 9y agoGenuinely curious - Why? We were considering doing so at one point for PtP links (equiv to a /30 or a /31 if you area really bleeding edge) - but then decided that there wasn't any reason to not just use /64s everywhere. I take your point though - it certainly is theoretically (and in practice) possible to doing something other than a /64 - I've just never seen it in the wild.
- cesarb 9y agoI have heard of one good reason: with a /64, someone sending packets to random addresses within that /64 will fill up the neighbor cache, while with a smaller network like a /126, that can't happen.