Turning On Network Debugging

You can set systemd-networkd to work in debug mode so that you can analyze log files with debugging information to help troubleshoot networking problems.

You can turn on network debugging by adding a drop-in file in /etc/systemd to customize the default systemd configuration in /usr/lib/systemd.

Procedure

1. Run the following command as root to create a directory with the name systemd-networkd.service.d, including the .d extension.

mkdir -p /etc/systemd/system/systemd-networkd.service.d/

2. Run the following command as root to establish a systemd drop-in unit with a debugging configuration for the network service.

cat > /etc/systemd/system/systemd-networkd.service.d/10-loglevel-debug.conf << "EOF"
[Service]
Environment=SYSTEMD_LOG_LEVEL=debug
EOF

3. Reload the systemctl daemon and restart the systemd-networkd service for the changes to take effect.

systemctl daemon-reload
systemctl restart systemd-networkd

4. Verify your changes.

systemd-delta --type=extended

5. View the log files by running this command.

journalctl -u systemd-networkd

6. After debugging the network connections, turn debugging off by deleting the drop-in file.

rm /etc/systemd/system/systemd-networkd.service.d/10-loglevel-debug.conf