After a seemingly innocuous update my Ubuntu 22.04.5 LTS system no longer auto-configures ipv4 networking on ethernet or wifi interfaces. Ipv6 works fine and manually configuring ipv4 works fine.
Here is the apt history from the offending update:
libpskc0:amd64 (2.6.7-3build1, 2.6.7-3ubuntu0.1),
cups-filters:amd64 (1.28.15-0ubuntu1.3, 1.28.15-0ubuntu1.4),
ovmf:amd64 (2022.02-3ubuntu0.22.04.2, 2022.02-3ubuntu0.22.04.3),
google-chrome-stable:amd64 (129.0.6668.70-1, 129.0.6668.100-1),
ubuntu-advantage-desktop-daemon:amd64 (1.10~22.04.1, 1.10.ubuntu0.22.04.2),
libfontembed1:amd64 (1.28.15-0ubuntu1.3, 1.28.15-0ubuntu1.4),
cups-filters-core-drivers:amd64 (1.28.15-0ubuntu1.3, 1.28.15-0ubuntu1.4),
nodejs:amd64 (20.17.0-1nodesource1, 20.18.0-1nodesource1),
cups-browsed:amd64 (1.28.15-0ubuntu1.3, 1.28.15-0ubuntu1.4),
brave-browser:amd64 (1.70.119, 1.70.126),
code:amd64 (1.93.1-1726079302, 1.94.2-1728494015),
kubectl:amd64 (1:494.0.0-0, 1:496.0.0-0),
libcupsfilters1:amd64 (1.28.15-0ubuntu1.3, 1.28.15-0ubuntu1.4),
ruby-webrick:amd64 (1.7.0-3, 1.7.0-3ubuntu0.1)
I've tried rolling back libpskc0 and nodejs with no effect. The previous version of ovmf is not available in the repo.
Here is a manual configuration that works (/etc/NetworkManager/system-connections/Wired\ connection\ 1.nmconnection):
[connection]
id=Wired connection 1
uuid=a9d94420-f026-3f3f-bfdd-8142ae130e71
type=ethernet
autoconnect-priority=-100
[ethernet]
[ipv4]
address1=192.168.0.123/24,192.168.0.1
dns=8.8.8.8;
method=manual
[ipv6]
addr-gen-mode=stable-privacy
method=auto
[proxy]
And an automatic one that doesn't:
[connection]
id=Wired connection 1
uuid=a9d94420-f026-3f3f-bfdd-8142ae130e71
type=ethernet
autoconnect-priority=-100
[ethernet]
[ipv4]
method=auto
[ipv6]
addr-gen-mode=stable-privacy
method=auto
[proxy]
Here's the result of ifconfig with the non-working automatic config:
enx089204536db9: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet6 2601:207:680:29e2:d864:1ed3:f424:6a31 prefixlen 64 scopeid 0x0<global>
inet6 fe80::b92c:2b5:5510:e58b prefixlen 64 scopeid 0x20<link>
inet6 2601:207:680:29e2:fb45:144e:3353:9272 prefixlen 64 scopeid 0x0<global>
ether 08:92:04:53:6d:b9 txqueuelen 1000 (Ethernet)
RX packets 40433 bytes 39759055 (39.7 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 18507 bytes 7483707 (7.4 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
lo: flags=73<UP,LOOPBACK,RUNNING> mtu 65536
inet 127.0.0.1 netmask 255.0.0.0
inet6 ::1 prefixlen 128 scopeid 0x10<host>
loop txqueuelen 1000 (Local Loopback)
RX packets 16119 bytes 1722379 (1.7 MB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 16119 bytes 1722379 (1.7 MB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
virbr0: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
inet 192.168.122.1 netmask 255.255.255.0 broadcast 192.168.122.255
ether 52:54:00:78:d9:8c txqueuelen 1000 (Ethernet)
RX packets 0 bytes 0 (0.0 B)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 0 bytes 0 (0.0 B)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
wlp0s20f3: flags=4099<UP,BROADCAST,MULTICAST> mtu 1500
ether 4c:03:4f:c3:f5:5f txqueuelen 1000 (Ethernet)
RX packets 23 bytes 6925 (6.9 KB)
RX errors 0 dropped 0 overruns 0 frame 0
TX packets 33 bytes 6203 (6.2 KB)
TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0
Any thoughts on what could have caused this? How to fix? I don't mind manually configuring my wired connection, but this is a laptop and doing that for every new wifi connection will be a serious hassle.
Thanks for any help.
Umm. The solution to this problem is to always check your router. I spent a significant amount of time trying to solve this before my phone disconnected from the wifi and wouldn't reconnect. Turns out my linksys router decided to stop giving out DHCP leases on ipv4 for some reason.
A router restart solved it. Let's all hope I'm smarter next time.