Hello.
A long time ago I open this thread : https://forums.opensuse.org/showthre...on-in-journald
Here one solution.

Step one :
Configure the router to send logs on local network ( In my case just put the IP address of the receiver which must listen port 514 )

Step two :

From this site : https://unix.stackexchange.com/quest...emd-arch-linux

Install socat
Create a fake syslog server
Code:
#  This file is part of systemd.
#
#  systemd is free software; you can redistribute it and/or modify it
#  under the terms of the GNU General Public License as published by
#  the Free Software Foundation; either version 2 of the License, or
#  (at your option) any later version.
#
#
#    from starfry
#    https://unix.stackexchange.com/questions/83173/receiving-syslog-messages-with-a-systemd-arch-linux
#
#
#
#    Installed : /etc/systemd/system/fake_syslog.service
#    use : Nothing
#
[Unit]
Description=poor man's syslog server

[Service]
Restart=on-success
ExecStart=/usr/bin/socat -u UDP-RECV:514 STDOUT

[Install]
WantedBy=multi-user.target
Enable and start the service

Step three Test it :
Watch systemd journal
Code:
systemd-journalctl  -f
Log in on the rooter.
send a message locally to syslog
Code:
logger "This is a test"
That's all.