Re: MDNS?

[Tom H <tomh0665@gmail.com>]

On Fri, Feb 24, 2012 at 9:14 AM, Tony van der Hoff <tony@vanderhoff.org> wrote:
>
> Hi, I'm trying to install WINE on my squeeze amd64 system. The configurator
> throws up a message box:
>
>  It appears that libnss-mdns is installed on your system,
>  but lib32nss-mdns is not. Please note that Wine will not be
>  able to access the Internet unless you either install
>  lib32nss-mdns (or ia32-libnss-mdns), or uninstall libnss-mdns.
>
> I guess the 32-bit libraries are inappropriate, but is it safe to uninstall
> libnss-mdns? It doesn't seem to have any dependencies, and as far as I'm
> aware I've no use for mDNS.

Uninstalling "libnss-mdns" _might_ break avahi and therefore anything
that uses it - but that's just an guess...

It looks like the difference between " libnss-mdns" and
"lib32nss-mdns" is that "lib32nss-mdns" is meant to bring in
"libc6-i386" because "This is the 32bit version of the library, meant
for AMD64 systems" - although "lib32nss-mdns" is described as "is
built for 32-bits environments" which I find somewhat confusing.

root@vishaala:~# apt-cache show libnss-mdns
Package: libnss-mdns
Source: nss-mdns
Version: 0.10-3.2
Installed-Size: 144
Maintainer: Utopia Maintenance Team
<pkg-utopia-maintainers@lists.alioth.debian.org>
Architecture: amd64
Depends: libc6 (>= 2.2.5), base-files (>= 3.1.10), avahi-daemon (>= 0.6.16-1)
Suggests: avahi-autoipd | zeroconf
Description-en: NSS module for Multicast DNS name resolution
 nss-mdns is a plugin for the GNU Name Service Switch (NSS) functionality
 of the GNU C Library (glibc) providing host name resolution via Multicast
 DNS (using Zeroconf, aka Apple Bonjour / Apple Rendezvous ), effectively
 allowing name resolution by common Unix/Linux programs in the ad-hoc mDNS
 domain .local.
<snip>

root@vishaala:~# apt-cache show lib32nss-mdns
Package: lib32nss-mdns
Source: nss-mdns
Version: 0.10-3.2
Installed-Size: 120
Maintainer: Utopia Maintenance Team
<pkg-utopia-maintainers@lists.alioth.debian.org>
Architecture: amd64
Depends: libc6-i386 (>= 2.1.3), base-files (>= 3.1.10), avahi-daemon
(>= 0.6.16-1)
Suggests: avahi-autoipd | zeroconf
Conflicts: libc6-i386 (<= 2.9-18)
Description-en: NSS module for Multicast DNS name resolution (32-bits version)
 nss-mdns is a plugin for the GNU Name Service Switch (NSS) functionality
 of the GNU C Library (glibc) providing host name resolution via Multicast
 DNS (using Zeroconf, aka Apple Bonjour / Apple Rendezvous ), effectively
 allowing name resolution by common Unix/Linux programs in the ad-hoc mDNS
 domain .local.
 .
 This package is built for 32-bits environments.
<snip>

root@vishaala:~# apt-cache show libc6-i386
Package: libc6-i386
Source: eglibc
Version: 2.13-26
Installed-Size: 8440
Maintainer: GNU Libc Maintainers <debian-glibc@lists.debian.org>
Architecture: amd64
Replaces: libc6-dev-i386
Depends: libc6 (= 2.13-26)
Breaks: fakechroot (<< 2.9-1.1), fakeroot (<< 1.12.3), fglrx-glx-ia32
(<< 1:9-6-1), gnu-efi (<< 3.0e-3), ia32-libs (<< 20090804),
ia32-libs-gtk (<< 20090804), lib32asound2 (<< 1.0.20-3),
lib32asound2-dev (<< 1.0.20-3), lib32bz2-1.0 (<< 1.0.5-3),
lib32bz2-dev (<< 1.0.5-3), lib32ffi-dev (<< 3.0.9~rc9-1), lib32ffi5
(<< 3.0.9~rc9-1), lib32g2c0 (<< 1:3.4.6-10), lib32gcc1 (<< 1:4.4.0-7),
lib32gfortran3 (<< 4.4.0-7), lib32gmp3 (<< 2:4.3.1+dfsg-3),
lib32gmp3-dev (<< 2:4.3.1+dfsg-3), lib32gmpxx4 (<< 2:4.3.1+dfsg-3),
lib32gomp1 (<< 4.4.0-7), lib32icu-dev (<< 4.0.1-3), lib32icu40 (<<
4.0.1-3), lib32mudflap0 (<< 4.4.0-7), lib32ncurses5 (<<
5.7+20090523-1), lib32ncurses5-dev (<< 5.7+20090530-1), lib32ncursesw5
(<< 5.7+20090530-1), lib32ncursesw5-dev (<< 5.7+20090530-1),
lib32nss-mdns (<< 0.10-3.1), lib32objc2 (<< 4.4.0-7), lib32readline5
(<< 5.2-5), lib32readline5-dev (<< 5.2-5), lib32stdc++6 (<< 4.4.0-7),
lib32stdc++6-4.4-dbg (<< 4.4.0-7), lib32z1 (<< 1:1.2.3.3.dfsg-14),
lib32z1-dev (<< 1:1.2.3.3.dfsg-14), libc6-dev-i386 (<< 2.9-15),
nvidia-glx-ia32 (<< 185.18.14-2), nvidia-libvdpau1-ia32 (<<
185.18.14-2)
Description-en: Embedded GNU C Library: 32-bit shared libraries for AMD64
 This package includes shared versions of the standard C
 library and the standard math library, as well as many others.
 This is the 32bit version of the library, meant for AMD64 systems.
<snip>

On an i386 box:

root@sidnetbook:~# apt-cache show lib32nss-mdns
N: Can't select versions from package 'lib32nss-mdns' as it is purely virtual
N: No packages found
root@sidnetbook:~# apt-cache show libc6-i386
N: Can't select versions from package 'libc6-i386' as it is purely virtual
N: No packages found