FS#47572 - [systemd] IPv6 gateway get autoconfigured on all VLAN interfaces when only one VLAN receives RA

Attached to Project: Arch Linux
Opened by Tao (gongtao0607) - Wednesday, 30 December 2015, 20:00 GMT
Last edited by Dave Reisner (falconindy) - Saturday, 18 June 2016, 13:51 GMT
Task Type Bug Report
Category Packages: Core
Status Closed
Assigned To Thomas Bächler (brain0)
Dave Reisner (falconindy)
Architecture i686
Severity Medium
Priority Normal
Reported Version
Due in Version Undecided
Due Date Undecided
Percent Complete 100%
Votes 0
Private No

Details

Description:
1. Ethernet, enp8s4 configured vlan as vlan99, vlan100, vlan101, vlan200.
2. Each vlan bridged to a separate linux bridge: br-wan, br-lan, br-tm, br-guest.
3. vlan99 receives icmpv6 router advertisement from ISP, every couple of seconds.
4. All vlan99, vlan100, vlan101, vlan200, enp8s4, br-wan, br-lan, br-tm, br-guest get default gateway configured!
--------
default via fe80::deeb:94ff:feb5:7c22 dev vlan200 proto ra metric 1024 pref medium
default via fe80::deeb:94ff:feb5:7c22 dev enp8s4 proto ra metric 1024 pref medium
default via fe80::deeb:94ff:feb5:7c22 dev vlan101 proto ra metric 1024 pref medium
default via fe80::deeb:94ff:feb5:7c22 dev vlan99 proto ra metric 1024 pref medium
default via fe80::deeb:94ff:feb5:7c22 dev vlan100 proto ra metric 1024 pref medium
default via fe80::deeb:94ff:feb5:7c22 dev br-lan proto ra metric 1024 pref medium
default via fe80::deeb:94ff:feb5:7c22 dev br-tm proto ra metric 1024 pref medium
default via fe80::deeb:94ff:feb5:7c22 dev br-wan proto ra metric 1024 pref medium
default via fe80::deeb:94ff:feb5:7c22 dev br-guest proto ra metric 1024 pref medium
--------
5. Double checked only the vlan99 receives router advertisement by tcpdump(enp8s4 receives too, under tcpdump, if that count)
tcpdump -ni $IFACE ip6 and icmp6 and 'ip6[40] = 134'

The interesting thing is, first, vlan99 shouldn't get configured because it is raw interface for br-wan. Second the enp8s4 shouldn't get a packet since it is a native vlan interface. Third, the rest, just seemed weird.

Additional info:
* package version(s)
Latest i686 version:
Linux 4.2.5-1-ARCH #1 SMP PREEMPT Tue Oct 27 08:28:41 CET 2015 i686 GNU/Linux

* config and/or log files etc.
1. Used a OpenWRT router(Netgear WNDR3800) to encapsulation ISP wan port to vlan99, as well as providing lan port by untagging other vlans.
-------------
config switch
option name 'switch0'
option reset '1'
option enable_vlan '1'
option enable_vlan4k '1'
option blinkrate '2'

config switch_vlan
option device 'switch0'
option vlan '100'
option ports '0t 2 3 5t'

config switch_vlan
option device 'switch0'
option vlan '101'
option ports '0t 5t'

config switch_vlan
option device 'switch0'
option vlan '200'
option ports '0t 5t'

config switch_vlan
option device 'switch0'
option vlan '99'
option ports '0t 1 5t'
------------
2. The router advertisement also reached OpenWRT's ethernet with vlan tag 99, seems to be fine
--------------
12: eth0.99@eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500
inet6 fe80::4494:fcff:fe91:b408/64 scope link
valid_lft forever preferred_lft forever

default via fe80::deeb:94ff:feb5:7c22 dev eth0.99 proto ra metric 1024 expires 1798sec hoplimit 64
--------------
3. The systemd-networkd configuration:
enp8s4.network:
--------
[Match]
Name=enp8s4
[Network]
VLAN=vlan99
VLAN=vlan100
VLAN=vlan101
VLAN=vlan200
-------
vlan100.netdev:
-------
[NetDev]
Name=vlan100
Kind=vlan
[VLAN]
Id=100
-------
vlan100.network:
-------
[Match]
Name=vlan100
[Network]
DHCP=no
Bridge=br-lan
------
br-lan.netdev
------
[NetDev]
Name=br-lan
Kind=bridge
------
br-lan.network
------
[Match]
Name=br-lan
[Network]
Address=172.25.100.1/24
------
All rest vlans and the bridges are similar.
4. brctl show
-----
bridge name bridge id STP enabled interfaces
br-guest 8000.ea71b9715dd9 no vlan101
br-lan 8000.9648b2867606 no vlan100
br-tm 8000.6aee42745af5 no vlan200
br-wan 8000.b2b85766c735 no vlan99
-----

Steps to reproduce:
1. Configure an ethernet port with vlan.
2. Send a router advertisement (with vlan tag) to that port
3. Should able to see all vlan interfaces including the native interface auto configured the gateway.
4. One step further, if vlan interface bridged to a bridge interface, both bridge interface and vlan interface autoconfigured the gateway.
This task depends upon

Closed by  Dave Reisner (falconindy)
Saturday, 18 June 2016, 13:51 GMT
Reason for closing:  Fixed
Additional comments about closing:  systemd-230-5
Comment by Thomas Bächler (brain0) - Wednesday, 06 January 2016, 22:58 GMT Comment by Wilhelm Schuster (wlhlm) - Friday, 03 June 2016, 19:20 GMT
Upstream issue was fixed in master (should land in 231 or backport[?]): https://github.com/systemd/systemd/pull/3294

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