We are experiencing a service failure in the systemd-network-generator.service, indicated by the error 'Failed to parse kernel command line: Invalid argument'. This issue has also been observed in another cluster configured with IPv6.

4.15.0-0.nightly-2023-12-19-033450
Network type: OVNKubernetes, Dualstack (IPv4 primary)
on top of
RHOS-16.2-RHEL-8-20230510.n.1

Consistently reproducible under the specified conditions.

Deploy an OCP cluster on OSP with a dualstack configuration. 

The systemd-network-generator.service fails with the error "Failed to parse kernel command line: Invalid argument".

systemd-network-generator.service should operate without failure under the given configuration.

$ oc get nodes
NAME                          STATUS   ROLES                  AGE   VERSION
ostest-w5ddc-master-0         Ready    control-plane,master   82m   v1.28.4+7aa0a74
ostest-w5ddc-master-1         Ready    control-plane,master   82m   v1.28.4+7aa0a74
ostest-w5ddc-master-2         Ready    control-plane,master   82m   v1.28.4+7aa0a74
ostest-w5ddc-worker-0-7fzqp   Ready    worker                 64m   v1.28.4+7aa0a74
ostest-w5ddc-worker-0-wcdpf   Ready    worker                 64m   v1.28.4+7aa0a74
$ oc debug -q node/ostest-w5ddc-master-0 -- chroot /host sudo systemctl list-units --failed
  UNIT                              LOAD   ACTIVE SUB    DESCRIPTION
● systemd-network-generator.service loaded failed failed Generate network units from Kernel command lineLOAD   = Reflects whether the unit definition was properly loaded.
ACTIVE = The high-level unit activation state, i.e. generalization of SUB.
SUB    = The low-level unit activation state, values depend on unit type.

$ oc debug node/ostest-w5ddc-master-0
Starting pod/ostest-w5ddc-master-0-debug-nnkr8 ...
To use host binaries, run `chroot /host`
Pod IP: 192.168.192.189
If you don't see a command prompt, try pressing enter.
sh-4.4# chroot /host
sh-5.1# sudo systemctl status systemd-network-generator.service
× systemd-network-generator.service - Generate network units from Kernel command line
     Loaded: loaded (/usr/lib/systemd/system/systemd-network-generator.service; enabled; preset: enabled)
     Active: failed (Result: exit-code) since Wed 2023-12-20 13:44:46 UTC; 1h 27min ago
       Docs: man:systemd-network-generator.service(8)
   Main PID: 748 (code=exited, status=1/FAILURE)
        CPU: 6msDec 20 13:44:46 ostest-w5ddc-master-0 systemd-network-generator[748]: Failed to parse kernel command line: Invalid argument
Dec 20 13:44:46 ostest-w5ddc-master-0 systemd[1]: systemd-network-generator.service: Main process exited, code=exited, status=1/FAILURE
Dec 20 13:44:46 ostest-w5ddc-master-0 systemd[1]: systemd-network-generator.service: Failed with result 'exit-code'.
Dec 20 13:44:46 ostest-w5ddc-master-0 systemd[1]: Failed to start Generate network units from Kernel command line.
sh-5.1# sudo journalctl -u systemd-network-generator.service
Dec 20 13:41:38 ostest-w5ddc-master-0 systemd[1]: Finished Generate network units from Kernel command line.
Dec 20 13:44:18 ostest-w5ddc-master-0 systemd[1]: systemd-network-generator.service: Deactivated successfully.
Dec 20 13:44:18 ostest-w5ddc-master-0 systemd[1]: Stopped Generate network units from Kernel command line.
-- Boot 146b11d61e7248e1a5a3ef7bd7fcf182 --
Dec 20 13:44:46 ostest-w5ddc-master-0 systemd-network-generator[748]: Failed to parse kernel command line: Invalid argument
Dec 20 13:44:46 ostest-w5ddc-master-0 systemd[1]: systemd-network-generator.service: Main process exited, code=exited, status=1/FAILURE
Dec 20 13:44:46 ostest-w5ddc-master-0 systemd[1]: systemd-network-generator.service: Failed with result 'exit-code'.
Dec 20 13:44:46 ostest-w5ddc-master-0 systemd[1]: Failed to start Generate network units from Kernel command line.