19 Jan
2023
19 Jan
'23
3:43 a.m.
Here in SE Massachusetts Comcast was doing IPv6 prefix delegation that
was handing out a 60-bit prefix, not 64. They'd also hand out a single
address. Like my IPv4 address, barring a replacement cable modem, I
never noticed anything changing but didn't keep a super close eye on
them either.
I say "was doing" simply because FIOS just put fiber on the poles and
we switched. And Verizon hands out a /56 prefix like they're supposed
to.
Jim
On Wed, Jan 18, 2023 at 7:43 PM Paul Koning <paulkoning(a)comcast.net> wrote:
It seems that Comcast IPv6 is (a) an address, and (b) a 64 bit prefix. There is no
relationship between the two. The easiest to use is the address, but that is known to
change. I haven't kept an eye on the prefix to see if that has remained stable. The
prefix is a bit harder to use. I got some machinery to propagate it to my home nodes but
that stuff (in Linux) seems to be fragile.
paul
> On Jan 18, 2023, at 5:39 PM, Keith Halewood <Keith.Halewood(a)pitbulluk.org>
wrote:
>
> Hi Mark,
>
> How 'static' is your IPv6 address? According to the Comcast documentation
I've seen/read, it seems their customers are allocated a 64bit prefix that never
changes. Everything under that is apparently directly addressable, subject to your
firewall rules.
> If that's the case, and you eventually get your IPv6 service back again, perhaps
it would be better to connect here (A29RT2, 29.2) via that route on port 60010. Firewall
rules here don't do DNS lookups - it's all IP address lists.