[ipv6hackers] "Stick to limited IPv6 deployments, businesses warned"

Fernando Gont fgont at si6networks.com
Mon Sep 10 22:50:28 CEST 2012

On 09/10/2012 04:03 AM, Doug Barton wrote:
>> I'm arguing for RDNSS implementation. They are not mutually exclusive.
> No, but having the 2 things overlap for any given number of options
> makes implementors' jobs much harder.

Nowadays, the situation is actually worse: you need both DHCPv6 *and*
RAs for many scenarios, since none of them can provide everything that's

>>> The other issue that comes up often in these discussions is the idea of
>>> administrative separation between the people who run the routers, and
>>> the people who handle things like DNS and DHCP. Most enterprises want
>>> this separation preserved.
>> And they can have it with DHCP.
> No, they can't. SLAAC is mandatory at this point in the process (well,
> RA is, but you get the idea).

Mandatory from an IETF perspective -- but hosts do send DHCPv6-requests
when they do not receive RAs, anyway.

(FWIW, IPsec was mandatory from the IETF's point of view, too --- you
get the idea :-) )

>> What's wrong with making RDNSS available to the environments that want it?
> Having 2 ways to provision the same thing makes implementors' jobs harder.

Well, so far we're heading to having all vendors support at least basic
RAs and basic DHCPv6 -- at which point "not implementing RDNSS" does not
make any sense at all.

>>> SLAAC was an interesting idea for the simple provisioning of dumb
>>> devices. Anything more exciting requires DHCP. It's very unfortunate
>>> that the anti-DHCP contingent is still fighting a battle that they lost
>>> 12 years ago, and delaying wider IPv6 rollout as a result.
>> I completely disagree here. There are many environments where 99%
>> of the desktop users just need an address, DNS servers, and a default
>> route. In a lot of those environments, the guy running DNS is the same
>> guy running the routers. SLAAC+RDNSS is useful in those environments.
> And those same environments could have gotten the same minimal
> configuration from DHCP, just like they do for IPv4 now.

FWIW, if I had to choose between SLAAC and DHCPv6, I'd most likely go
for DHCPv6, for the very simple reason that it is the same conept as in
the IPv4 case -- which is certainly a good thing.

That said, and given the current state of affairs (and given my notes
above), I'd go with full DHCPv6 and SLAAC+RDNSS, and let each operator
decide. -- and if some vendor decides not to implement something, good
for them.

>> Why is it that the DHCP-heads can't understand that pro-SLAAC is not
>> inherently anti-DHCP?
> Maybe because the pro-SLAAC folks have waged war against a complete
> DHCPv6 implementation from day 1?

Because they think they know better, in the same way you argue that we
should be doing DHCPv6 for everything?

Fernando Gont
SI6 Networks
e-mail: fgont at si6networks.com
PGP Fingerprint: 6666 31C6 D484 63B2 8FB1 E3C4 AE25 0D55 1D4E 7492

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