RA & DHCP problem...

[Mikael Abrahamsson]

On Mon, 30 Dec 2013, Roger Jørgensen wrote:

> What is wrong with having something else than our _current_ RAs to 
> provide defaultgateway on a network if the operator wish so? Let that be 
> DHCPv6 or dibbler?

Because the current method is known to work and you haven't given 
convincing arguments why it doesn't or why doing what you want is superior 
enough to warrant having two (or more) ways to do this?

When I first looked into IPv6 I was of your opinion, why not do it the 
same way it's done in IPv4. Then I got over it. Operationally, I don't see 
having default gateway in DHCPv6 as something that makes much sense, apart 
from the fact that it means people have to learn less to start using IPv6, 
which I don't consider a valid use-case.

For me, RA/RS/ND is all one single thing, you can't make IPv6 function 
without ND, so there is little reason to try to avoid the RA/RS machinery.

A more valid use-case would be if you were propagating for new 
functionality and said that this would be easier to implement in DHCPv6 
than in ND, and then you would get default-gw for free. That is the path I 
would choose. Unfortunately, the use-case that comes to mind (having 
routers that shouldn't have ::/0 pointed to them) is already implemented 
in by means of RIO in RAs. There is just very little deployed support for 
it as far as I know.

-- 
Mikael Abrahamsson    email: swmike at swm.pp.se