The Reg does 240/4

Tue Feb 13 07:07:35 UTC 2024

The angst around ipv6 on hackernews that this triggered was pretty
revealing and worth thinking about independently.
https://news.ycombinator.com/item?id=39316266

In the tik world, people are struggling to deploy ipv6 as even linux
kernel 5.7 in routerOS 7.XX still has some needed missing features. It
also appears 240 ain´t working there, either. And routerOS is one of
the more up to date platforms.

if I could use the controversy to talk to why it has been so hard to
deploy ipv6 to the edge and how to fix that problem instead rather
than triggering people, it would be helpful.

...

I was inspired to try a couple traceroutes. It used to be 240 escaped
my prior comcast router and wandered around a while; it does not do
that anymore. I would be dryly amused if that box was actually running
my old OpenWrt bcp38 stuff which blocked 240 for a couple years. My
cloud works, my aws stack works, openwrt works.

My comcast ipv6 connection is LOVELY - ssh stays nailed up for days. I
still reflexively use mosh because it survives me moving from AP to
AP.

I do wish there was some way I could escape the painful policy debate
and just focus on the code-related problems. (my position is basically
that all new devices not waste cycles blocking the 240 and 0/8 ranges,
and merely it move it from reserved for bezos^H^H^H^H^Hfuture use to
unicast and recognize deployed reality).

Peering into a murky crystal ball, say, 5 years in the future:

Another thing that I worry about is port space exhaustion, which is
increasingly a thing on firewalls and CGNs. If I can distract you - in
this blog cloudflare attempted to cut the number of ipv4 addresses
they use from 2 to 1, after observing some major retry issues. With a
nice patch, reducing the problem.

https://blog.cloudflare.com/linux-transport-protocol-port-selection-performance/

Their problems remain the same if they also just use one ipv6 address
(which would be silly, of course). QUIC is going to make this worse.

In there, they mention udp-lite, but don´t mention that this protocol
has worked for over a decade, and has all this unallocated port space.
Firewalling and natting it is easy.

Peering further into the soi-distant decades ahead, perhaps we should
just allocate all the remaining protocol space in the IP header to a
quic native protocol, and start retiring the old ones.

/me hides

On Tue, Feb 13, 2024 at 1:21 AM Jay R. Ashworth <jra at baylink.com> wrote:
>
> I know we had a thread on this last month, but I can't remember what it
> was titled.
>
> ElReg has done a civilian-level backgrounder on the 240/4 issue, for anyone
> who wants to read and scoff at it.  :-)
>
> https://www.theregister.com/2024/02/09/240_4_ipv4_block_activism/
>
> Cheers,
> -- jra
>
> --
> Jay R. Ashworth                  Baylink                       jra at baylink.com
> Designer                     The Things I Think                       RFC 2100
> Ashworth & Associates       http://www.bcp38.info          2000 Land Rover DII
> St Petersburg FL USA      BCP38: Ask For It By Name!           +1 727 647 1274

-- 
40 years of net history, a couple songs:
https://www.youtube.com/watch?v=D9RGX6QFm5E
Dave Täht CSO, LibreQos