V6 still not supported (was Making Use of 240/4 NetBlock)

Tim Howe tim.h at bendtel.com
Wed Mar 9 19:07:18 UTC 2022

On Wed, 9 Mar 2022 09:46:41 -0800
David Conrad <drc at virtualized.org> wrote:

> Tim,
> On Mar 9, 2022, at 9:09 AM, Tim Howe <tim.h at bendtel.com> wrote:
> > Some of our biggest vendors who have supposedly supported
> > v6 for over a decade have rudimentary, show-stopping bugs.  
> Not disagreeing (and not picking on you), but despite hearing this
> with some frequency, I haven’t seen much data to corroborate these
> sorts of statements.

	Heh :)  This is kind of funny for me since I am usually far
more likely to be accused of not being able to shut up about it.  I
don't like to throw vendors under the bus publicly, but I will instead
name some positive actors whose efforts I appreciate:
	Juniper fixed their DHCPv6 relay server when I was able to show
them it was not working correctly; they have also had other bugs that
were DHCPv6 related and provided work-arounds and fixes (they still
have a few bugs that appear to be the result of incomplete fixes for
related issues).  I'm still not sure if they ever fixed the fact that
SRX routers can't dynamically add the default v6 route (I still had to
hard code this last time I tested on SRX320; the bug is documented).
	Of course, it still feels like not-that-long-ago when Juniper
wanted me to buy a special license for each switch that I wanted to use
OSPFv3 on.  That's no longer a thing, but it made me pretty mad at the

	ZyXel has been very responsive to adding support, fixing
functionality, and working with me on in-depth and long term testing of
issues.  I'm not sure I have ever worked with a vendor that was so
responsive to my requests and reports.  This is in sharp contrast to
one of their competitors who basically told me they have no interest in
adding the IPv6 support they had previously told me they could add.

	Adtran is the only vendor I know of that has DHCPv6 option-18
support in their gpon/xgspon OLT cards.  They have also fixed v6 DNS
issues that we have reported on their 5000 chassis.  If it weren't for
their OLTs I would probably not know what "working" looks like.  They
are also the only vendor that has ever handed me a Broadcom based CPE
to test that worked out of the box.  Sadly, I have problems with most
of their current gen; the 515ac is a bright spot - someone important
must be buying these who insisted on v6 support.  There are still some
minor issues with MAC tables on the OLTs that have only revealed
themselves over time, but nothing show-stopping (just requires minor
manual intervention in some cases).

	The ISC's Kea DHCP server is a must have for us; this org
deserves more recognition and support from the community.  We use it
for prefix delegation and option-18 (basically all dhcpv6 is relayed

	I have still not seen an ACS that has equiv v6 support, but I
will say that both Adtran and Calix appear to be making /very recent/
efforts and have shown progress in this regard.

	Ubiquiti Edge routers have pretty decent IPv6 support at the
CLI, but the web GUIs expose little to none of it.

	Of course shout out to Microsoft Windows for great support
going back a long way; I wouldn't use it, but the efforts help us all.
The OpenBSD team are also rock stars.


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