[Pkg-utopia-maintainers] Bug#800364: network-manager does not remove default IPv6 route with kernel 4.1/4.2

[Björn Lässig]

Package: network-manager
Version: 1.0.6-1
Severity: normal

Dear Maintainer,

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When using network-manager with a wired connection, it does not remove
the default IPv6 route when running with kernel 4.1 or 4.2.
The Route is removed running under kernel 3.16

It was reproducible on 2 laptops running under debian testing/unstable.

When plugging in the routes are: (using ip -6 r)
2001:1234:1234:1234::/64 dev eth0  proto ra  metric 100 
fe80::/64 dev eth0  proto kernel  metric 256 
default via fe80::5054:ff:1234:1234 dev eth0  proto static  metric 100 
After unplug:
default via fe80::5054:ff:1234:1234 dev eth0  proto static  metric 100 

This breaks networking with non-wired connections afterwards (higher metric)

The IPv4 routes are removed cleanly.

Im am using a little executable script as a workaround
=====================================================
File: /etc/network/if-post-down.d/remove_default_route
#! /bin/bash
ip -6 route flush dev $IFACE
=====================================================

Network-manager connection config
=====================================================
File: /etc/NetworkManager/system-connections/Ethernet
[connection]
id=eth0-dhcp
uuid=75c185ce-edf2-4704-99a7-509905ea3782
type=ethernet
interface-name=eth0
permissions=
secondaries=

[ethernet]
duplex=full
mac-address=F0:DE:F1:AB:6C:A1
mac-address-blacklist=

[ipv4]
dns-search=
method=auto

[ipv6]
dns-search=
ip6-privacy=0
method=auto
=====================================================

-- System Information:
Debian Release: stretch/sid
  APT prefers oldoldstable-proposed-updates
  APT policy: (500, 'oldoldstable-proposed-updates'), (500, 'unstable'), (500, 'testing'), (500, 'stable'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 3.16.0-4-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages network-manager depends on:
ii  adduser                3.113+nmu3
ii  dbus                   1.10.0-2
ii  init-system-helpers    1.23
ii  isc-dhcp-client        4.3.3-3
ii  libbluetooth3          5.33-1
ii  libc6                  2.19-19
ii  libdbus-1-3            1.10.0-2
ii  libdbus-glib-1-2       0.102-1
ii  libglib2.0-0           2.44.1-1.1
ii  libgnutls-deb0-28      3.3.17-1
ii  libgudev-1.0-0         230-2
ii  libmm-glib0            1.4.10-1
ii  libndp0                1.4-2
ii  libnewt0.52            0.52.18-1
ii  libnl-3-200            3.2.26-1
ii  libnl-genl-3-200       3.2.26-1
ii  libnl-route-3-200      3.2.26-1
ii  libnm0                 1.0.6-1
ii  libpam-systemd         226-1
ii  libpolkit-agent-1-0    0.112-1
ii  libpolkit-gobject-1-0  0.112-1
ii  libreadline6           6.3-8+b3
ii  libsoup2.4-1           2.50.0-2
ii  libsystemd0            226-1
ii  libteamdctl0           1.18-1
ii  libuuid1               2.27-1
ii  lsb-base               9.20150826
ii  policykit-1            0.112-1
ii  udev                   226-1
ii  wpasupplicant          2.3-2.1

Versions of packages network-manager recommends:
ii  crda            3.13-1
ii  dnsmasq-base    2.75-1
ii  iptables        1.4.21-2+b1
pn  iputils-arping  <none>
ii  modemmanager    1.4.10-1
ii  ppp             2.4.6-3.1

Versions of packages network-manager suggests:
ii  avahi-autoipd  0.6.31-5
pn  libteam-utils  <none>

-- Configuration Files:
/etc/NetworkManager/NetworkManager.conf changed:
[main]
plugins=ifupdown,keyfile
auth-polkit=no
[ifupdown]
managed=false

-- no debconf information