Re:Hello IPv6: a minimal tutorial for IPv4 users
by elktea on Thursday October 07, 2021 @06:09PM
(#28792733)
regarding (1), the route table growth is actually not slowing. as we run out of IPv4 addresses there is more fragmentation as bigger blocks are split up and sold.
Re:Hello IPv6: a minimal tutorial for IPv4 users
by fulafel on Friday October 08, 2021 @12:24AM
(#28795735)
In graphs I saw it slowed somewhat.. but even if you are right, this is still waste of router memory since those same routes could be for much bigger v6 blocks instead of tiny v4 ones.
And also, in absolute terms it's currently tiny, ~ 2 M routes that can be represented in a couple of addrs worth of space each in line card memory when deciding just which interface to forward, and keeping in mind that only core routers that don't outsource transit to other upstream telcos have a need to keep this in memory.
But consider: (1) that for ages the route table growth has been slow due to v4 shortage, and router memory has kept getting cheaper on the normal memory cost curve for this plateau phase in history, and (2) Consumer ISPs have been abusing this and making prefixes jump around even on CPE reboots, instead of having them stable for months and years like is the design, and (3) mechanisms to smooth out renumbering haven't been deployed because ISPs have gotten away with doing [2] without any mitigations.
The 'net infra could probably afford to start giving many more people portable blocks, and it would be only fair that ISPs would have to pay a bit for their sins regarding [2], and to this would add incentives to do [3].