[Pkg-exim4-users] dc_minimaldns not working?

[Lothar Ketterer]

Hi,

On Sat, Mar 15, 2008 at 11:35:33AM +0100, Marc Haber wrote:
> Interesting. I have installed etch r2 in a virtual machine, and see
> the AAAA lookups as well. However, when I dpkg-reconfigure exim4 for
> minimaldns, the AAAA lookups seem to vanish on my test system.

If this is only a problem on my box and not etch in general, it's ok
then. I solved it for me as described in my previous posts.

> I would think that there should be a different loopback address for
> IPv6 as well, but I don't know enough about IPv6, and for me, setting
> minimaldns eliminates the lookups on exim startup

I looked into this today. For IPv4, RFC 3330 (Special-Use IPv4
Addresses) [1] says:

  127.0.0.0/8 - This block is assigned for use as the Internet host
  loopback address.

Regarding IPv6, RFC 4291 (IP Version 6 Addressing Architecture) [2]
states

  Address type         Binary prefix        IPv6 notation   Section
  ------------         -------------        -------------   -------
  ...
  Loopback             00...1  (128 bits)   ::1/128         2.5.3
  ...

and in Section 2.5.3 (The Loopback Address):

  The unicast address 0:0:0:0:0:0:0:1 is called the loopback address.

Seems like IPv6 has only one loopback address.

If you agree that the solution then is to append the hostname to the
line beginning with "::1" in /etc/hosts, i wanted to suggest to include
this in Section 1.3.7 of the FAQ, like this:

  Add an IPv6 record for your hostname (listed in /etc/hostname)
  to /etc/hosts by creating a line that says
    ::1             ip6-localhost ip6-loopback <your_hostname>
  If there is already a line starting with "::1", append your hostname
  to it. You can check with "getent hosts your_hostname" whether
  this was successful.

What do you think about it?

1. http://tools.ietf.org/html/rfc3330
2. http://tools.ietf.org/html/rfc4291

> > Then why is an IPv6 entry for the hostname given during installation
> > missing?
> 
> I guess because it hasn't been implemented yet.

But /etc/hosts contains IPv6 entries after installation? Looks like it
is just the hostname that is missing.

> Sorry that I am not a big help. I do not see the issue

Never mind and thanks for your time!

Regards,
Lothar