[radvd-devel-l] RDNSS Option

Pekka Savola pekkas at netcore.fi
Thu Mar 9 14:31:58 EST 2006

On Thu, 9 Mar 2006, Mickaël Guérin wrote:
>> However, the lifetime and preference values are the same for all the
>> DNS server addresses sent using one option, right?
> No, you can put several dns servers and each server can have a different
> preference and lifetime (like specified in the ietf draft).

Correct, but then each DNS server address must be carried in a 
separate RDNSS option, which causes overhead.  So, you should be able 
to avoid that in case you don't need separate lifetime/preference 
values for RDNSS_1, RDNSS_2, and RDNSS_3.

> I agree, but this (different lifetime & preference) was a need we 
> had (the work was done at school, so we had to follow the teacher's 
> instructions -- the teacher was working on working on ad-hoc network 
> but I've never understood his needs ;) ) I think it's better to 
> follow the draft, there are maybe cases where it can be usefull.

OK, if there is a need for specifying different preferences (I can see 
how that could be useful, maybe it's something that should be changed 
in the draft as a matter of fact), maybe both approaches should be 
supported:  multiple RDNSS options and a single RDNSS option with 
multiple DNS addresses.

Do you agree that multiple DNS servers in a single RDNSS statement 
should also be supported?

Pekka Savola                 "You each name yourselves king, yet the
Netcore Oy                    kingdom bleeds."
Systems. Networks. Security. -- George R.R. Martin: A Clash of Kings

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