The really valuable prefixes are those with are stable and have good reputation on them.. Everything else is junk these days..
>IPv6 would only promote incautious distribution which would again result in address space exhaustion
There are more ipv6 addresses than there are atoms in the earth. Exhaustion won't be a concern for generations.
>more abuse and increased cybercrime.
IP address-based mitigations are already not effective with v4, can you talk about why v6 makes this worse?
AtlasBarfed•1mo ago
I mean a million is objectively a large number if it's all on paper, but to me, that's not a particularly large data set for talking about the entire freaking internet.
And how cheap of a SOC can handle that in memory? A better question might be to even make a system on a chip that couldn't handle that memory?
_bernd•1mo ago
slyall•1mo ago
orangeboats•1mo ago
486sx33•1mo ago
teraflop•1mo ago
For instance, Comcast (AS 7922) owns about 2^26 IPv4 addresses, distributed across 149 different prefixes. Almost all of these prefixes are non-contiguous with each other, so they each require separate routing table entries. Comcast can't consolidate those routes without swapping IP address blocks with other networks, and it can't grow its address space without acquiring new small blocks. (Since no more large blocks are available, as this article discusses.)
In contrast, Comcast owns about 2^109 IPv6 addresses, which are covered by just 5 prefixes (two big ones of 2^108 each, and three smaller ones). It can freely subdivide its own networks within those prefixes, without ever running out of addresses, and without having to announce new routes.
cryptonector•1mo ago
Since we don't have time machines probably the best solution is to refuse prefix portability.
rcxdude•1mo ago
tptacek•1mo ago
jandrese•1mo ago
tptacek•1mo ago
colmmacc•1mo ago
On the IPv6 side; by 2002, nobody was really experimenting with A6 records any more, and EUI64 was needless. Both were parts of IPv6 designed to facilitate "easy" renumbering, so that single prefixes could be replaced with larger ones. But the ISPs weren't complaining any more about table size.
jandrese•1mo ago
toast0•1mo ago
Routers had to get better (more tcam capacity) because there wasn't much choice. Nobody wants to run two border routers each with the table for half the /8s or something terrible like that. And you really can't aggregate /24 announcements when consecutive addresses are unrelated.
toast0•1mo ago
The small hosting provider I use has I think 7 v4 prefixes, but could be one v6 prefix (if they supported v6 which they sadly don't). Maybe not --- a lot of their /22s are advertised as four /24s to allow for a DDoS Mitigation provider to attract traffic when needed; but it'd probably still be fewer prefixes with v6.
Not every ASN looks the same, but many of them would advertise a lot fewer prefixes if they could get contiguous addresses, but it's not possible/reasonable to get contiguous allocations for v4.
Since the routing table is organized around prefixes, if there is complete migration, the routing table will probably be smaller.