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/override.conf
    	[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