Which command would you use to clear the DNS cache on a Linux system?

To clear the DNS cache on a Linux system, using the command to restart the DNS service is effective. This approach ensures that any cached DNS entries are purged, facilitating fresh queries to be made upon the next name resolution request. In many Linux distributions, the command sudo service dns-clean restart specifically targets the DNS cache management service that handles cache clearing efficiently.

The command utilizes 'sudo' to gain the necessary privileges, 'service' to manage existing services, and 'dns-clean restart' to invoke the DNS cleanup process, ensuring that the DNS cache is cleared properly. This method is widely accepted for systems utilizing the dns-clean service, which is responsible for maintaining cache integrity.

Other options may either not apply directly to Linux environments or be misleading regarding their functionality. For instance, simply using 'clear dns' lacks the necessary context or recognized syntax to manipulate DNS settings effectively. Restarting a service generally requires the service name and may not guarantee a cache clearance, as just "restart dns" does not specify the required service management context. The command structure 'systemctl restart dns.service' is valid for systemd environments, but this approach may not be applicable to all distributions and does not explicitly confirm that DNS resolution caches are being cleared as expected.