To:
Bob Hinden <hinden@iprg.nokia.com>
cc:
John Schnizlein <jschnizl@cisco.com>, Soohong Daniel Park <soohong.park@samsung.com>, dnsop@cafax.se
From:
Doug Barton <DougB@dougbarton.net>
Date:
Wed, 1 Oct 2003 12:04:27 -0700 (PDT)
In-Reply-To:
<4.3.2.7.2.20031001105114.02e7d1c0@mailhost.iprg.nokia.com>
Sender:
owner-dnsop@cafax.se
Subject:
Re: How IPv6 host gets DNS address
On Wed, 1 Oct 2003, Bob Hinden wrote: > John, > > >This apparent efficiency - one packet per link rather than 2 per host - > >would come at the cost of the hosts waiting until the next scheduled > >multicast RA. Where would the two-packet exchange be more detrimental > >than a random delay until DNS is available? > > The host learns about the router via a Router Advertisement (RA) so having > it use the same mechanism to learn the addresses of a DNS server doesn't > add any extra delay. Having all the information in one RA seems like a > clear win to me as compared to using RAs to learn about routers and link > info, and then (perhaps in parallel, but I am not sure about that) have > each host use a two packet DHCPv6 exchange to get the addresses of the > recursive DNS servers. The problem with this argument is that it's a slippery slope. It sounds totally reasonable to say, "As long as we have X, we might as well include Y." However, the address(es) of the recursive name servers aren't that useful without a search list. Then, once you get into a windows environment you really need the netbios name server address.... etc. Once you get done with that, you've invented something that looks an awful lot like dhcp. Doug -- If you're never wrong, you're not trying hard enough. #---------------------------------------------------------------------- # To unsubscribe, send a message to <dnsop-request@cafax.se>.