can't connect to .local hostnames (avahi-daemon by default?)

[Jonathan Marsden]

On 06/23/2012 05:39 AM, ∅ wrote:

> I didn't install avahi-anything on any machine (though maybe it
> installed with some other package) nor did I intend to rely on mDNS.
> If it was not installed intentionally or unintentionally by me, it
> came with 11.10.

Please retest -- do a fresh 11.10 installation and check whether
avahi-daemon is installed by default.  I'll do the same test here later
today if I have the time.

I note that in 12.04, lubuntu-core Recommends: avahi-daemon (but does
not Depends: on it).  This means that an Lubuntu install using
Recommends would install avahi-daemon, but an install suppressing use of
Recommends would not necessarily do so.

> I will say, again, though, that dpkg -l |grep avahi on the new 12.04 
> install resulted in at least 4 avahi libs. So outside of the
> question as to whether or not the daemon is supposed to be there,
> what are the purpose of these?

That's a whole different question.  I'm not really sure it is relevant
to the issue you experienced, but I'll try to answer it anyway.

I'm not an Avahi/Bonjour/mDNS expert at all.  I decided a few years ago
I preferred to use more conventional DNS, since I've been managing
networks and DNS using BIND since at least 1994.  If someone else on the
list is expert in this stuff, please speak up!

My best guess at this point is that the avahi-related libraries which
are installed by default in Lubuntu 12.04 are all avahi client
libraries, they are not server libraries.  The avahi-daemon package and
binary is, as far as I understand it, the server component of avahi.

It is possible, and often sensible, to install a DNS client library
(libbind9-80) without running a DNS server (bind9), or an SSH client
(openssh-client) without also running the openssh server
(openssh-server), or a web browser (chromium-browser) without running a
web server (apache2)!

Logically, I suspect (but have not 100% confirmed!) that it is
appropriate for workstations to install an avahi client
(libavahi-client3 and related packages) but not necessarily to install
the corresponding server package (avahi-daemon).  In this case the
corresponding "server" package is called avahi-daemon (why they didn't
follow long-standing Debian/Ubuntu convention and name that package
avahi-server, I do not know!).

The only valid reason I can think of for installing avahi-daemon by
default would be that we want all Lubuntu machines to advertize some
services to the network using the Bonjour/mDNS protocols.  And I'm not
sure we want that.  Do you know why we would want to do that?

Jonathan