[avahi] Multicast DNS and the Unicast .local Domain

[Lennart Poettering]

On Fri, 19.06.09 19:19, Carsten Strotmann (carsten at strotmann.de) wrote:

> Hi,
> 
> I stumbled over the topic I describe below when I updated an Ubuntu 
> System from Version 8.04 tro 9.04. Avahi refused to start because I have 
> a unicast ".local" domain in my network(s).
> 
> This behavior is documented as recommended for distributions in the 
> Avahi Wiki at
> http://avahi.org/wiki/AvahiAndUnicastDotLocal
> 
> I think this is a not well thought out decision. It would be a good 
> decision if it would detect a "used" unicast ".local" domain, but in my 
> case, the ".local" domain is one of many "pseudo" domains that are 
> configured as "empty" DNS zones on all resolving DNS Servers on the 
> network edge (border to the Internet), to prevent any "pseudo TLD" like 
> ".local" to be leaked into the Internet and hitting the Root DNS Server 
> System.

This is simply broken. Your DNS server should not return a working SOA
for .local. If at all your DNS server should always return NXDOMAIN
for all .local names, overriding the internet .local SOA.

Lennart

-- 
Lennart Poettering                        Red Hat, Inc.
lennart [at] poettering [dot] net
http://0pointer.net/lennart/           GnuPG 0x1A015CC4