Why used DHCPv6 when RA has RDNSS and DNSSL?

[Fernando Gont]

On 31/3/20 15:21, James R Cutler wrote:
> Golly whiz, I have always considered DHCPv6 and RA/SLAAC as 
> configuration tools for end systems. In addition, I have always 
> considered the configuration of end systems to be the (implicit)) 
> responsibility of the end system owner, not the network provider. I 
> would love to find someone who could eloquently articulate why the end 
> system owner (especially in managed environments) can not choose how to 
> configure end systems.

Because the network admin can always choose to drop his/her packets if 
he/she does not behave as expected. Whether you like it or not, the 
network admin rules.


> Why must the availability of these two particular configuration tools 
> become such a partisan/religious debate. 

Because there are folks that believe they know better than the folk 
running the network.



> Does it make a significant 
> difference in the cost of providing network services? Does it make a 
> significant difference in the cost of end systems? I can find no 
> evidence of this in the debate.

There is not. It's a religious debate.



> It seems obvious that (non-superuser) home systems have configuration 
> requirements different from those in managed offices. Getting these 
> satisfied to meet business requirements requires thought at a higher 
> protocol level (such as Business Operations) and division of 
> labor/control is often useful. Forcing end system configuration 
> management into router configurations conflicts with end system change 
> control. In many situations SLAAC, an obviously router-centric function, 
> meets basic addressing requirements without burdening router operations 
> with end system details. It many, often overlapping, situations DHCPv6 
> offers an orthogonal management point for items such as NTP, DNS, 
> Printers, and more without interfering with managing the routing network.
> 
> Wouldn’t it be more cost effect in the long term to simply make SLAAC 
> and DHCPv6 cooperative and complementary attributes of end-to-end 
> networking?

They should have enough features such that net admin can pick whatever 
of these two they please.

SLAAC has incorporated RDNSS/DNSSL. So the only thing left if DHCPV6 
being able to configure a default route. (And Android to support it, you 
might say).

Thanks,
-- 
Fernando Gont
e-mail: fernando at gont.com.ar || fgont at si6networks.com
PGP Fingerprint: 7809 84F5 322E 45C7 F1C9 3945 96EE A9EF D076 FFF1