This bug was fixed in the package ifupdown - 0.7ubuntu1

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ifupdown (0.7ubuntu1) quantal-proposed; urgency=low

  * Resynchronise with Debian experimental.  Remaining changes:
    (LP: #298488, LP: #663352)
    - ifupdown.nw: Use 100 as default route metric unless an explicit metric
      parameter is set in /etc/network/interface.
    - If the /etc/NetworkManager/NetworkManager.conf file is present
      but doesn't have the "ifupdown:managed" the previous upload instructed
      the iniparser to return -1, which evaluates to TRUE. We instead instruct
      it to return 0, as we shouldn't prevent ifupdown from managing the
      interfaces in that case, as NM won't either. (LP: #281984)
    - debian/postinst: If the loopback interface is missing from the config
      in /etc/network/interfaces, add it on upgrade.
    - Add jobs and hooks for upstart.
  * Cherry-pick commit 011d5904c09d from upstream, fixing cases where the
    error messages wouldn't be triggered (caused test failure).
  * Cherry-pick commit 7c1a226cc995 from upstream, adds support for two
    options on dhcpv6 (accept_ra and autoconf) (LP: #1013597)
  * Cherry-pick commit 5af7e814faee from upstream, fixing a failure in the
    example script generate-interfaces.pl (LP: #286808)
  * Cherry-pick commit a1f8efc4d93f from upstream, add --no-scripts as a
    parameter to ifup/ifdown, allowing the user to bypass the the scripts
    in /etc/network/if-*.d/ (LP: #258782)

ifupdown (0.7) unstable; urgency=low

  * Accept duplicate options in /etc/network/interfaces, join them using
    a newline as a delimiter.
  * If an interface isn't defined, but mentioned in auto or allow statement,
    don't mention it in ifquery output.
  * Change shortcut for --exclude to -X (was -e previously).
  * Make ifquery return false if the interface isn't defined.
  * Fix typos in the changelog.
  * Calculate broadcast address internally.
  * Allow concurrent netmask specification in both address (using CIDR
    notation) and netmask for IPv6 (Closes: #674775).
  * Add preferred-lifetime setting for IPv6.
  * Pass -w and -e options to sysctl so we still can configure an interface
    even if IPv6 SLAAC options can't be set for some reason.
  * Port to GNU/Hurd (thanks to Svante Signell, closes: #296115).
  * Chdir to root when executing external programs (Closes: #361964).
  * Remove updetach from PPP method (Closes: #675016).
  * Configure hotplug interfaces only if they're running (thanks to Evgeni
    Golov, closes: #673658).
  * Rewrite NEWS file (Closes: #673688).
  * Update examples (Closes: #340992).
  * Update tests.
  * Update README.

ifupdown (0.7~rc3) unstable; urgency=low

  * Upload to unstable.
  * Don't refer to README from netbase any more.
  * Internal changes:
    - Make set_variable() able to set variables conditionally.
    - Improve conversions interface.
    - Add some support for interface link configuration.
    - Don't leak memory in some functions.
  * Configure VLANs automatically (Closes: #520436).
  * Calculate netmask internally, so even if a user haven't supplied
    one or have used CIDR notation, hook scripts will have it properly
    specified in IF_NETMASK environment variable.
  * Declare Breaks/Replaces relationship against netbase << 5.0.
  * Merge changes from Ubuntu (thanks to Stéphane Graber):
    - Mark package as Multi-Arch: foreign.
    - Update statefile paths in the 'contrib' scripts and in the
      noweb source.
  * Temporarily unapply patch for #547587.
  * Update tests.
 -- Stephane Graber <email address hidden>   Thu, 28 Jun 2012 17:21:45 -0400