[Bug 120186] Re: network unavailable where .local domain is used

[Ubuntu721]

The full message (translate by myself with Google, from French to English) is :
Research network services disabled
Your current network has a domain .local, which is not recommended, not compatible with the search function Avahi network service. this function has been disabled.

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Title:
  network unavailable where .local domain is used

Status in “avahi” package in Ubuntu:
  Invalid

Bug description:
  I upgraded 2 weeks ago to Linux Mint Cassandra (based on Fiesty) and have the following problem when trying to use my computer at the hotel I stay at weekly:
  When I first booted up at the hotel this week there appeared a message for a short period of time: "network service discovery disabled. your current network has a .local domain, which is not recommended and incompatible with the avahi (sp?)" and the rest of the message disappeared before I could make note of it. this message only appeared on the initial bootup and not subsequent bootups.

  I checked ipconfig in Windows XP and get the following info:
  dns suffix: hamptoninn.lan
  ip address 169.254.11.87
  subnet mask: 255.255.255.248
  dfault gateway: 10.71.0.1
  dhcp server : 10.71.0.1
  dns servers: 10.61.32.1
  1.1.1.1

  
  In linux mint Cassandra i show the following:

  internet address: 169.254.11.87
  broadcast address: 169.254.11.87
  mask: 255.255.255.248

  
  roaming mode is not checked
  configuration is dhcp

  dns servers: 10.61.32.1
  1.1.1.1
  search domains: hamptoninn.lan

  This is the same as last week, but since last week i put a new hard
  drive in this laptop and did a clean install of both Windows XP and
  Linux Mint Cassandra.

  I did run "sudo dhclient" and got the following:

  Internet Systems Consortium DHCP Client v3.0.4
  Copyright 2004-2006 Internet Systems Consortium
  All Rights Reserved
  For info, please visit http://www.isc.org/sw/dhcp

  Listening on LPF/eth0/00:12:3f:cf:df:f9
  Sending on LPF/eth0/00:12:3f:cf:df:f9
  Sending on Socket/fallback
  DHCP DISCOVER on eth0 to 255.255.255.255 port 67 interval 7
  DHCPOFFER from 10.71.0.1
  DHCPREQUEST on eth0 to 255.255.255.255 port 67
  DHCPACK from 10.71.0.1
  SIOCADDRT: Network is unreachable
  bound to 169.254.11.87 - - renewal in 14226 seconds

  I found the following material at the avahi.org website, but being a
  computer networking neophyte, i am not sure what it means:

  "Avahi and Unicast Domains .local ¶

  mDNS/DNS-SD is inherently incompatible with unicast DNS zones .local.
  We strongly recommend not to use Avahi or nss-mdns in such a network
  setup.

  Background: The Zeroconf protocols Avahi implements are known as mDNS
  and DNS-SD. mDNS (short for Multicast DNS) is based on traditional
  (unicast) DNS, but the two systems do not interact. mDNS is used to
  manage a special cooperative zone .local where all local mDNS servers
  can freely register host names or services. Before mDNS was introduced
  the domain .local was sometimes used in non-public (unicast) DNS
  servers to assign names in LANs. Unfortunately some networks still use
  this domain that way. If Avahi and nss-mdns is installed properly a
  machine does not contact a unicast DNS server when resolving names
  from the .local domain, thus the unicast DNS domain .local becomes
  unreachable.

  If you come across a network where .local is a unicast DNS domain, please contact the local administrator and ask him to move his DNS zone to a different domain. If this is not possible, we recommend not to use Avahi in such a network at all.
  Workarounds ¶

  If you really want to use Avahi with .local as unicast domain, you
  might want to try the following. YMMV. Don't come running to us if
  something doesn't work as expected. It's your own fault!

  The recommended nss-mdns configuration line for /etc/nsswitch.conf is

  hosts: files mdns4_minimal [NOTFOUND=return] dns mdns4

  This makes nss-mdns authoritative for .local. If this is changed as
  follows, unicast DNS will be tried before mDNS for .local, essentially
  "merging" the unicast and the multicast domain .local, with unicast
  taking precedence.

  hosts: files dns mdns4

  Please note that this line will "unbreak" the name service switch
  (NSS, aka gethostbyname()) only. Avahi itself will still not resolve
  any hosts from a unicast domain .local. i.e. this change will make
  some things work, but not all.

  Please remember, that we do no recommend using nss-mdns in this way.
  Why? Firstly, because the conflict resolution protocol of mDNS becomes
  ineffective. Secondly, because due to the "merging" of theses zones,
  DNS RRs might point to wrong other RRs. Thirdly, this can become a
  security issue, because information about the mDNS domain .local which
  is intended to be link-local might leak into the Internet. Fourthly,
  when you mistype host names from .local the long mDNS timeout will
  always occur. Fifthly it creates more traffic than necessary. And
  finally it is really ugly. "

  I looked at /etc/nsswitch.conf  and the line there was:
  hosts: files dns 
  which i commented out and added:
  hosts: files dns mdns4
  ( there was no line "hosts: files mdns4_minimal [NOTFOUND=return] dns mdns4" in that conf file as it existed.)
  this change did not help and i reverted it back to the original and gave up.

  What do I do.  If this Hotel uses .local and avahi can't deal with it,
  there must be a lot of hotels doing so.

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