FS#41477 - [networkmanager] duplicate scope link routes

Attached to Project: Arch Linux
Opened by Daniel Wendler (BMRMorph) - Tuesday, 05 August 2014, 14:45 GMT
Last edited by Jan de Groot (JGC) - Wednesday, 11 October 2017, 08:32 GMT
Task Type Bug Report
Category Packages: Extra
Status Closed
Assigned To Jan de Groot (JGC)
Jan Alexander Steffens (heftig)
Architecture x86_64
Severity High
Priority Normal
Reported Version
Due in Version Undecided
Due Date Undecided
Percent Complete 100%
Votes 9
Private No

Details

Description:

in latest NetworkManager there are 2 scope link routes when establishing an connection, one with an metric and one without:

ip r
default via 10.114.100.1 dev wifi0 proto static metric 1024
10.114.100.0/24 dev wifi0 proto kernel scope link src 10.114.100.24
10.114.100.0/24 dev wifi0 proto kernel scope link src 10.114.100.24 metric 303

it makes no difference if this is an wifi or an cabled connection:

ip r
default via 10.114.100.1 dev lan0 proto static metric 1024
10.114.100.0/24 dev lan0 proto kernel scope link src 10.114.100.24
10.114.100.0/24 dev lan0 proto kernel scope link src 10.114.100.24 metric 202

As we have an 1to1 mapping MAC to IP adress over both connection types my whole routing table looks then:

ip r
default via 10.114.100.1 dev lan0 proto static metric 1024
10.114.100.0/24 dev lan0 proto kernel scope link src 10.114.100.24
10.114.100.0/24 dev wifi0 proto kernel scope link src 10.114.100.24
10.114.100.0/24 dev lan0 proto kernel scope link src 10.114.100.24 metric 202
10.114.100.0/24 dev wifi0 proto kernel scope link src 10.114.100.24 metric 303

This behavior breakes my connections as the scope link routes without metric are used round robin.
The problem could be resolved if i delete the scope link routes without metric.

Additional info:
* Version: extra/networkmanager (0.9.10.0-2)


Steps to reproduce:
Connect any network and show routing table.
This task depends upon

Closed by  Jan de Groot (JGC)
Wednesday, 11 October 2017, 08:32 GMT
Reason for closing:  Fixed
Additional comments about closing:  dhcp is internal by default now.
Comment by ray65526 (ray65536) - Sunday, 07 September 2014, 10:32 GMT
I have identical problem too.

extra/networkmanager 0.9.10.0-4

Comment by Lubos Kolouch (kolcon) - Thursday, 11 September 2014, 10:20 GMT
same problem here...
Comment by Maxime de Roucy (akira86) - Saturday, 15 November 2014, 23:15 GMT
The route with metric comes from dhcpd. If you tweak dhcpd.conf or switch to dclient you get only one route… unfortunately it's the one without metric.
Comment by Daniel Wendler (BMRMorph) - Monday, 17 November 2014, 07:55 GMT
Ok, when dhcpcd inserted the routes with metric (the wanted one), who inserted the routes without metric.
As i don't have the problem bevor the specific Network Manager version, there must be something there.
Maybe someone have an hint to prevent inserting routes without metric.
Comment by Maxime de Roucy (akira86) - Monday, 17 November 2014, 08:05 GMT
> who inserted the routes without metric

nm-dhcp-helper does
Comment by Saad Malik (SimFox3) - Sunday, 08 February 2015, 22:05 GMT
Any updates on this?
Comment by Jan Alexander Steffens (heftig) - Sunday, 08 February 2015, 22:07 GMT
This is probably an upstream bug and should be discussed there.
Comment by Maxime de Roucy (akira86) - Saturday, 21 February 2015, 11:02 GMT
> This is probably an upstream bug and should be discussed there.

Yes you are right.
For my part I think you can close the bug.

As a workaround I suggest using the internal dhcp client of NetworkManager :
https://mail.gnome.org/archives/networkmanager-list/2014-December/msg00030.html

It can be done by addind the following line in the [main] section of /etc/NetworkManager/NetworkManager.conf
dhcp=internal

https://wiki.archlinux.org/index.php/NetworkManager#Configure_NetworkManager_to_use_a_specific_DHCP_client
Comment by Daniel Wendler (BMRMorph) - Saturday, 21 February 2015, 11:41 GMT
The workaround with the "dhcp=internal" settings seems to work.
By the way, since networkmanager-1.0.0-2 and the default usage of dhclient things become even more strange,
as with this client i got unpredictable metric settings on all route (default and scope link) every time i trigger an UP/DOWN event.

So as this is an upstream Problem, this bug could be closed.

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