Re: [BEHAVE] Happy Eyeballs and DNS64 not sending synthetic AAAA RRs

["Dan Wing" <[e-mail]>]

> -----Original Message-----
> From: Stephan Lagerholm [mailto:[e-mail]]
> Sent: Thursday, August 04, 2011 2:47 PM
> To: Dan Wing; Andrew Sullivan; [e-mail]
> Subject: RE: [BEHAVE] Happy Eyeballs and DNS64 not sending synthetic
> AAAA RRs
> 
> Thu 8/4/2011 3:25 PM, Dan Wing:
> > A nuance to this problem is that some networks will have a mix
> > of hosts:
> >
> >   (a) IPv4-only, which use a 'normal' DNS server
> >   (b) dual stack hosts, which use a 'normal' DNS server
> >   (c) IPv6-only hosts, which use a DNS64 server so they
> >       can use a NAT64 to visit IPv4-only servers.
> >
> > http://tools.ietf.org/html/draft-wing-behave-dns64-config-03
> discusses
> > the pros/cons of a bunch of mechanisms to provide the correct DNS
> > server to all three of those host types.
> 
> The technique outlined in the draft doesn't work. Clients will not
> strictly
> stick to the "ordered" list:
> 		::ffff:192.0.2.1       # 'normal' DNS server
> 		2001:db8:dddd::1234    # DNS64 server
> 
> If for example a client is trying to resolve
> www.dns-will-timeout-for-this-domain.com then the client will switch to
> the
> second DNS server in the list. In practice you will have about 50%
> traffic
> to each server after a day or so.
> 
> There are plenty of examples of domains that bind and other nameservers
> never return an answer for.
> 
> The right thing to do is to have different policies for the different
> networks, potentially using views or other similar DNS mechanism.

Can you write up how to accomplish that?

-d


> /Stephan Lagerholm