NetworkManager, default IPv4 route always through wifi, even if wired available

[Lionel]

If wifi is connected, the default IPv4 route is always through wifi, no route through wired connection is set up, even if wired faster, and connected to the same gw. The default IPv6 route is ok. Tested on a fresh install, same behavior.

lionel@lionelux:~$ ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host noprefixroute
       valid_lft forever preferred_lft forever
2: wlo1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UP group default qlen 1000
    link/ether 70:a8:d3:dc:fa:05 brd ff:ff:ff:ff:ff:ff
    altname wlp0s20f3
    inet 10.0.0.66/24 brd 10.0.0.255 scope global dynamic noprefixroute wlo1
       valid_lft 7153sec preferred_lft 7153sec
    inet6 2a01:e0a:51a:50d1:c4f5:20d5:51a:3666/64 scope global temporary dynamic
       valid_lft 604755sec preferred_lft 86110sec
    inet6 2a01:e0a:51a:50d1:3c79:4f2b:d7f1:a0d/64 scope global mngtmpaddr noprefixroute
       valid_lft forever preferred_lft forever
    inet6 fe80::e2e1:a4d7:bb8c:961a/64 scope link noprefixroute
       valid_lft forever preferred_lft forever
3: virbr0: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc noqueue state DOWN group default qlen 1000
    link/ether 52:54:00:4d:6c:56 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
       valid_lft forever preferred_lft forever
9: enx908d6e354c47: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether 90:8d:6e:35:4c:47 brd ff:ff:ff:ff:ff:ff
    inet 10.0.0.65/24 brd 10.0.0.255 scope global dynamic noprefixroute enx908d6e354c47
       valid_lft 7174sec preferred_lft 7174sec
    inet6 2a01:e0a:51a:50d1:7c69:4bd8:2924:9ff8/64 scope global temporary dynamic
       valid_lft 604775sec preferred_lft 86178sec
    inet6 2a01:e0a:51a:50d1:c87c:7002:3ad2:496e/64 scope global mngtmpaddr noprefixroute
       valid_lft forever preferred_lft forever
    inet6 fe80::ba1:bdae:e9c3:f29f/64 scope link noprefixroute
       valid_lft forever preferred_lft forever
10: enx186571a0c6a4: <NO-CARRIER,BROADCAST,MULTICAST,UP> mtu 1500 qdisc pfifo_fast state DOWN group default qlen 1000
    link/ether 18:65:71:a0:c6:a4 brd ff:ff:ff:ff:ff:ff

lionel@lionelux:~$ ip route
default via 10.0.0.1 dev wlo1 proto dhcp src 10.0.0.66 metric 600
10.0.0.0/24 dev wlo1 proto kernel scope link src 10.0.0.66 metric 600
192.168.122.0/24 dev virbr0 proto kernel scope link src 192.168.122.1 linkdown

lionel@lionelux:~$ ip -6 route
2a01:e0a:51a:50d1::/64 dev enx908d6e354c47 proto ra metric 100 pref medium
2a01:e0a:51a:50d1::/64 dev wlo1 proto ra metric 600 pref medium
fe80::/64 dev wlo1 proto kernel metric 1024 pref medium
fe80::/64 dev enx908d6e354c47 proto kernel metric 1024 pref medium
default via fe80::8b6b:4e44:c003:cca6 dev wlo1 proto ra metric 600 pref medium
default via fe80::8b6b:4e44:c003:cca6 dev enx908d6e354c47 proto ra metric 20100 pref medium

ProblemType: Bug
DistroRelease: Ubuntu 24.04
Package: network-manager 1.46.0-1ubuntu2
ProcVersionSignature: Ubuntu 6.8.0-31.31-generic 6.8.1
Uname: Linux 6.8.0-31-generic x86_64
ApportVersion: 2.28.1-0ubuntu2
Architecture: amd64
CRDA: N/A
CasperMD5CheckResult: pass
CurrentDesktop: ubuntu:GNOME
Date: Tue Apr 30 13:09:23 2024
InstallationDate: Installed on 2024-02-09 (81 days ago)
InstallationMedia: Ubuntu 23.10.1 "Mantic Minotaur" - Release amd64 (20231016.1)
IpRoute:
 default via 10.0.0.1 dev enx908d6e354c47 proto dhcp src 10.0.0.65 metric 100
 default via 10.0.0.1 dev wlo1 proto dhcp src 10.0.0.66 metric 600
 10.0.0.0/24 dev enx908d6e354c47 proto kernel scope link src 10.0.0.65 metric 100
 10.0.0.0/24 dev wlo1 proto kernel scope link src 10.0.0.66 metric 600
 192.168.122.0/24 dev virbr0 proto kernel scope link src 192.168.122.1 linkdown
NetworkManager.state:
 [main]
 NetworkingEnabled=true
 WirelessEnabled=true
 WWANEnabled=true
ProcEnviron:
 LANG=fr_FR.UTF-8
 PATH=(custom, no user)
 SHELL=/bin/bash
 TERM=xterm-256color
SourcePackage: network-manager
UpgradeStatus: Upgraded to noble on 2024-04-25 (5 days ago)
modified.conffile..etc.default.apport: [modified]
mtime.conffile..etc.default.apport: 2024-02-14T13:52:12.489815
nmcli-nm:
 RUNNING VERSION STATE STARTUP CONNECTIVITY NETWORKING WIFI-HW WIFI WWAN-HW WWAN
 running 1.46.0 connected started full enabled enabled enabled missing enabled

[Sebastien Bacher (seb128)]

Thank you for your bug report. Could you perhaps also submit it upstream on https://gitlab.freedesktop.org/NetworkManager/NetworkManager/-/issues ?