nanog mailing list archives

Re: IPv6 CPE best practices


From: Mark Andrews <marka () isc org>
Date: Fri, 17 Jul 2015 08:25:00 +1000


In message <02d301d0c012$b4f39130$1edab390$@gmail.com>, "Chuck Church" writes:
So, I've been following this IPv6 discussion for a while now.  Putting much
more thought into it than ever before.  What I've gathered so far:

 

We need both SLAAC and DHPCv6 on CPE router to support all end clients.

Yep.

Android and some other platforms still have some issues with a v6-addressed
DNS server (or don't use DHCPv6 at all), so you really need your
v4-addressed DNS server to hand out both AAAA and A records together.  Is
that close?

Only for really old clients or stupid clients that don't support
both.  DHCPv6 has supported handing out nameserver addresses for
over a decade (2003) so all clients SHOULD support this.  RDNSS was
only defined in 2010.

So giving each customer a /48 is the way to go.  How does one go about
configuring CPEs for devices to use this?  I'm aware of how DHCP-PD can dish
out a /48 of a larger block.

The DHCPv6 client on the upstream interface requests a PD.

Should I move to a standard CPE that supports
DHCP-PD (here is a list:  https://getipv6.info/display/IPv6/Broadband+CPE ,
some mention PD)?  Or should I just allow them to use any IPv6 compatible
router, and issue each customer a /48, but only configure a /64 of that
block for each CPE's inside interface (manual config).  Is there anything
other than DHCP-PD that can do this auto-magically?

The CPE divides the /48 up for local use and further assignment via
PD from its DHCP server.  If there is a CPE to old to do this you
may need to do manual assignment.  Your DHCP server should be able
to do both static and automatic PD.

Also see the homenet IETF working group.  It is working on providing
a standard home route that does this and source/destination based
routing so that homes can have multiple PA prefixes with traffic
going out the correct exit.  There are OpenWrt based routers that
implement this today.

Business class routers may not support fetching the prefix delegation
via PD but they are usually paying you more.

I support a small WISP occasionally, it's all wireless and Ethernet.
Several hundred small business customers.  Nothing super complicated.  Been
playing with an HE tunnel the last few days and found my netflow collector
works fine with FNF and IPv6, so making some progress.  Just wanting to
avoid any big mistakes when we think about getting some customers on it.

 

Thanks,

 

Chuck

 

-- 
Mark Andrews, ISC
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka () isc org


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