About domain name system (DNS) services
You can configure the domain name system (DNS) services for the Smoothwall Filter and Firewall to use. The default behavior is to use the internal DNS server, unless one has been specified during installation.
A DNS resolver translates domain names back into IP addresses. You can configure the Smoothwall Filter and Firewall to either use its own internal DNS proxy to resolve domain names or specify an external server to use. The default behavior is to use the internal DNS server, unless one has been specified during installation.
The DNS proxy service is used to provide internal and external name resolution services for local network hosts. You can configure a list of DNS servers for the DNS proxy service to use when resolving requests. You can also apply a load balancing pool to a specific DNS server to make sure that connections from your Internet Service Provider (ISP) are sent to their own DNS server. Most ISPs need this to make sure that requests to their DNS servers are made over their connections. For network devices to use the Smoothwall Filter and Firewall DNS proxy service, you must make sure that an access rule for DNS, on port 53, exists for the interface they use to connect.
You can configure a list of additional DNS servers to override the DNS servers configured in the DNS forwarders table within specific domains. For example, an Active Directory domain might need to query an internal DNS server for internal host names, rather than an external server.
Adding static DNS hosts means that the DNS proxy can override, or add to, external DNS resolutions. Host name to IP address mappings affect all hosts using the DNS proxy. However, your installation of the Smoothwall Filter and Firewall might not be configured to use the DNS proxy.
Note: The Smoothwall Filter and Firewall resolves static host names regardless of whether the DNS proxy service is turned on.