Re: SLAAC vs DHCPv6 (Re: RFC4941bis: consequences of many addresses for the network)

Fernando Gont <fgont@si6networks.com> Mon, 27 January 2020 21:46 UTC

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Subject: Re: SLAAC vs DHCPv6 (Re: RFC4941bis: consequences of many addresses for the network)
To: Brian E Carpenter <brian.e.carpenter@gmail.com>, Simon Hobson <linux@thehobsons.co.uk>, 6man WG <ipv6@ietf.org>
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From: Fernando Gont <fgont@si6networks.com>
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Date: Mon, 27 Jan 2020 18:44:23 -0300
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On 26/1/20 17:47, Brian E Carpenter wrote:
> On 27-Jan-20 09:22, Simon Hobson wrote:
>> Gyan Mishra <hayabusagsm@gmail.com> wrote:
>>
>>> The beauty behind SLAAC is that it works “out of the box” PNP like features makes it very user friendly to initiatally deploy.
>>
>> Remember that DHCP for IPv4 generally works "out of the box" for most users. Certainly in the SOHO market, the presence of a built in, auto-configured, and enabled DHCP server in the route means that the user just "plugs it in and it works". By the time you get to a level of network complexity where that isn't the case, then there is normally a network admin either on the staff or hired n as needed.
>>
>> If that isn't working reliably for users in the IPv6 world then that suggests the various components needed haven't reached the same level of completeness & correctness "mostly" available in the IPv4 world. It isn't an argument that DHCPv6 "doesn't work".
> 
> It's actually a historical accident. At the time that SLAAC was designed, DHCP(v4) wasn't mature and the state of the art in autoconfiguration was Appletalk, Novell IPX, and DECnet Phase IV. It really doesn't matter now. We can't roll the clock back.

Well, we *could* end the pointless religious battle, mandate both SLAAC 
and DHCPv6, and let admins and operators run their networks in whatever 
way they please.

Given the current state of affairs, in lots of places folks resort to 
doing *both* SLAAC + DHCPv6 (for various reasons), leadind to 
non-deterministic results, higher maintenance costs, more pain, etc.


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