# 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/ ``` 1. 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 ``` 1. Reload the `systemctl` daemon and restart the `systemd-networkd` service for the changes to take effect: ``` systemctl daemon-reload systemctl restart systemd-networkd ``` 1. Verify your changes: ``` systemd-delta --type=extended ``` 1. View the log files by running this command: ``` journalctl -u systemd-networkd ``` 1. 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 ```