[Pkg-utopia-maintainers] Bug#667676: network-manager: no dhcp6 answer flaps link, but neither managed nor other is set

[Per Carlson]

Package: network-manager
Version: 0.9.4.0-1
Severity: normal
Tags: ipv6

When using N-M in IPv6 automatic mode, it expects a DHCPv6 answer, and
if it's missing the link will flag. The timeout can be rather long, in 
this case ~3.5 hours, but the laptop have been in standby portions of 
the time frame.

Relevant IPv6 parts from /var/log/syslog:
Apr  5 18:23:51 apu NetworkManager[1344]: <info> Activation (wlan0)
Beginning IP6 addrconf.
Apr  5 21:05:58 apu NetworkManager[1344]: <info> (wlan0): canceled DHCP
transaction, DHCP client pid 11931
Apr  5 21:05:58 apu kernel: [18518.908356] wlan0: deauthenticating from
00:18:f8:f2:08:ac by local choice (reason=3)
Apr  5 21:06:01 apu wpa_supplicant[1364]: Trying to authenticate with
00:18:f8:f2:08:ac (SSID='jaddajadda' freq=2462 MHz)
Apr  5 21:06:01 apu wpa_supplicant[1364]: Trying to associate with
00:18:f8:f2:08:ac (SSID='jaddajadda' freq=2462 MHz)
Apr  5 21:06:01 apu kernel: [18522.792151] wlan0: authenticate with
00:18:f8:f2:08:ac (try 1)
Apr  5 21:06:01 apu kernel: [18522.794175] wlan0: authenticated
Apr  5 21:06:01 apu kernel: [18522.812850] wlan0: associate with
00:18:f8:f2:08:ac (try 1)
Apr  5 21:06:01 apu wpa_supplicant[1364]: Associated with
00:18:f8:f2:08:ac
Apr  5 21:06:01 apu kernel: [18522.815573] wlan0: RX ReassocResp from
00:18:f8:f2:08:ac (capab=0x411 status=0 aid=3)
Apr  5 21:06:01 apu kernel: [18522.815582] wlan0: associated
Apr  5 21:06:01 apu kernel: [18522.817145] ADDRCONF(NETDEV_CHANGE):
wlan0: link becomes ready
Apr  5 21:06:02 apu wpa_supplicant[1364]: WPA: Key negotiation completed
with 00:18:f8:f2:08:ac [PTK=CCMP GTK=CCMP]
Apr  5 21:06:02 apu wpa_supplicant[1364]: CTRL-EVENT-CONNECTED -
Connection to 00:18:f8:f2:08:ac completed (reauth) [id=0 id_str=]
Apr  5 21:06:02 apu NetworkManager[1344]: <info> Activation (wlan0)
Beginning IP6 addrconf.

My home router do not send RA's with O(ther) or M(anaged) flags set
so there isn't any DHCPv6 answer to wait for (unless it's trying to
get a PD, which makes no sense for a host).

pelle at apu:~$ rdisc6 -1 wlan0
Soliciting ff02::2 (ff02::2) on wlan0...

Hop limit                 :           64 (      0x40)
Stateful address conf.    :           No
Stateful other conf.      :           No
Router preference         :       medium
Router lifetime           :         1800 (0x00000708) seconds
Reachable time            :  unspecified (0x00000000)
Retransmit time           :  unspecified (0x00000000)
 Prefix                   : 2001:db8:9104:200::abba:babe/64
  Valid time              :        86400 (0x00015180) seconds
  Pref. time              :        14400 (0x00003840) seconds
 Recursive DNS server     : 2001:db8:2001::2:53
  DNS server lifetime     :          600 (0x00000258) seconds
 Source link-layer address: 00:18:F8:F2:08:AA
 from fe80::200:ff:fe00:0

pelle at apu:~$

As it's the whole link that is flapping makes both IPv4 and IPv6
connectivity flap, which makes this even worse.

I've tried other IPv6 modes in N-M, for example "Automatic, addresses
only" but with that one the IPv6 connectivity is really bad (maybe
another bug should be posted...) and "test-ipv6.com" reports a broken
system (2-3/10 if I recall correctly). With "automatic" I get a perfect 10/10. 
 
If I do turn off IPv6 (Ignore in N-M), I have a perfectly stable IPv4
link without any spurious link flaps.

Note: The changed N-M.conf is just me setting on loglevel debug
for IP6.

-- System Information:
Debian Release: wheezy/sid
  APT prefers testing
  APT policy: (600, 'testing'), (400, 'unstable')
Architecture: amd64 (x86_64)

Kernel: Linux 3.2.0-2-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.utf8, LC_CTYPE=en_US.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages network-manager depends on:
ii  adduser                3.113+nmu1
ii  dbus                   1.4.18-1
ii  dpkg                   1.16.2
ii  isc-dhcp-client        4.2.2.dfsg.1-4
ii  libc6                  2.13-27
ii  libdbus-1-3            1.4.18-1
ii  libdbus-glib-1-2       0.98-1
ii  libgcrypt11            1.5.0-3
ii  libglib2.0-0           2.30.2-6
ii  libgnutls26            2.12.18-1
ii  libgudev-1.0-0         175-3.1
ii  libnl-3-200            3.2.7-2
ii  libnl-genl-3-200       3.2.7-2
ii  libnl-route-3-200      3.2.7-2
ii  libnm-glib4            0.9.4.0-1
ii  libnm-util2            0.9.4.0-1
ii  libpolkit-gobject-1-0  0.104-2
ii  libuuid1               2.20.1-4
ii  lsb-base               3.2+Debian31
ii  udev                   175-3.1
ii  wpasupplicant          0.7.3-6

Versions of packages network-manager recommends:
ii  crda          1.1.2-1
ii  dnsmasq-base  2.60-2
ii  iptables      1.4.12.2-1
ii  modemmanager  0.5.2.0-1
ii  policykit-1   0.104-2
ii  ppp           2.4.5-5

Versions of packages network-manager suggests:
ii  avahi-autoipd  0.6.31-1

-- Configuration Files:
/etc/NetworkManager/NetworkManager.conf changed [not included]

-- no debconf information