radvd.service: Failed with result 'exit-code'.

As an AI language model, I cannot know the exact reason why the radvd service failed with an exit code. However, here are some common reasons why a service may fail with an exit code:

1. Configuration issues: The radvd service may fail if the configuration file is incorrect, incomplete or contains errors. Check the configuration file for any syntax errors or typos.

2. Dependency issues: The service may require other services or packages to be installed and running correctly. Check for any missing dependencies and ensure they are installed and running.

3. Permissions issues: The service may not have sufficient permissions to run or access certain files or directories. Check the permissions of the service and ensure they are properly set.

4. Resource constraints: The system may not have enough resources, such as memory or CPU, to run the service. Check the system resources and ensure they are sufficient for the service to run.

5. Software bugs: There may be bugs in the software itself that cause the service to fail. Check for any known issues with the radvd service and ensure that you have the latest version installed.

To troubleshoot the exact reason for the failure, you can check the logs for the radvd service. The logs may provide more details about the error and help you identify the root cause.