[190636] in North American Network Operators' Group
Re: New Office, New Network. Questions.
daemon@ATHENA.MIT.EDU (Owen DeLong)
Wed Jul 13 22:42:32 2016
X-Original-To: nanog@nanog.org
From: Owen DeLong <owen@delong.com>
In-Reply-To: <CAPkb-7DgDgipaGDqiObA6dENm+BhDqFSZVVzAL9Fz7_rxc72cw@mail.gmail.com>
Date: Wed, 13 Jul 2016 19:42:22 -0700
To: Baldur Norddahl <baldur.norddahl@gmail.com>
Cc: nanog@nanog.org
Errors-To: nanog-bounces@nanog.org
To provide some additional clarity and detail:
1. No, you can=E2=80=99t to the best of my knowledge hand out any =
IPv6
parameters via IPv4, nor should you really want to.
2. You can hand out IPv6 DNS resolver information from either or =
both
of SLAAC and DHCPv6.
For SLAAC, you=E2=80=99ll need routers that support RFC 6106. =
Juniper finally
added this in 14.1.
Cisco added it in 15.4(1)T, 15.3(2)S
More information here: =
https://en.wikipedia.org/wiki/Comparison_of_IPv6_support_in_operating_syst=
ems
To the best of my knowledge, DNS is a configuration option in =
all DHCPv6
implementations.
3. I disagree with Baldur about not bothering with IPv6 DNS =
resolvers.
Given that the long term goal is to get back to single-stack =
networking,
but with the single stack being IPv6, each and every vestigial =
IPv4
dependency you leave lying around is just another thing you need =
to clean
up at some point in the future. Since it=E2=80=99s so completely =
easy to enable
dual-stack (or even better IPv6-only) resolving when you first =
deploy
IPv6 to your end-systems, why not just do that?
Owen
> On Jul 13, 2016, at 15:53 , Baldur Norddahl =
<baldur.norddahl@gmail.com> wrote:
>=20
> "Is there a reason you use DHCPv6 and SLAAC? Is it for compatibility? =
Can I
> use the DHCPv4 to give out DNSv6 addresses?"
>=20
> Unless you plan om having IPv6 only hosts, there is no advantage in
> providing IPv6 DNS servers. Just stay with IPv4 for your DNS resolver =
in
> the DHCPv4 config. Notice that your IPv4 DNs resolver is perfectly =
capable
> of providing AAAA IPv6 replies.
>=20
> Using DHCPv6 in a corporate environment makes it easier to track which
> machine has an IP address as you can lookup the info in the DHCP lease
> database. Also some prefers the nice short addresses that you get from =
DHCP
> compared to SLAAC.
>=20
> My network has both enabled, so my tablet has the following two =
addresses:
>=20
> SLAAC: 2a00:7660:5c6:0:74cd:d48c:8230:a44f
> DHCP: 2a00:7660:5c6::701
>=20
> The later is easier to type if you have to add rules to your firewall =
etc.
>=20
> Regards
>=20
> Baldur
