Problems with NS*.worldnic.com

william(at)elan.net william at elan.net
Tue Apr 26 05:19:51 UTC 2005



On Tue, 26 Apr 2005 Valdis.Kletnieks at vt.edu wrote:

> On Mon, 25 Apr 2005 21:34:54 PDT, Rodney Joffe said:
>
>> I am not sure whether the correct solution is to "fix" dig so that is tries
>> ipv4, or to get the os "fixed" on a dual stack capable system so that if
>> there is not ipv6 connectivity it disables that part of the system.  I
>> suspect the first is appropriate, because there are obviously internal
>> processes that may validly want to use ipv6 even though there is no ipv6
>> connection.
>
> The problem is that you *could* have local/campuswide ipv6 connectivity,
> but not have an IPv6 connection to the outside world.  So my system comes
> up, it sees a Router Advertisement, it can get to other IPv6 systems that
> are 3-4 hops away.
>
> So how is it supposed to "know" that it doesn't have an ipv6 connection?
>
> Presumably the same way it "knows" it doesn't have an ipv4 connection when
> your OC-moby to the outside world falls over, but it's still perfectly able to
> talk to the entire rest of your corporate network....

Perhaps a solution is to specifically enable ipv6 dns resolution as 
preferable to ipv4 or the other way around. This could perhaps be
switch in resolv.conf or nsswitch.conf. Something like:

/etc/nsswitch.conf
...
hosts:  files  dns
dns-resolver:	AAAA  [NOTFOUND=return]  A6   A

Note: in this meaning NOTFOUND is only true when NXDOMAIN but not for NODATA

OR

/etc/resolv.conf
search example.com
protocol ipv6 ipv4

-- 
William Leibzon
Elan Networks
william at elan.net



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