This policy configures a local switch that can be used to disable DNS interception checks. The checks attempt to discover whether the browser is behind a proxy that redirects unknown host names.
This detection may not be necessary in an enterprise environment where the network configuration is known, since it causes some amount of DNS and HTTP traffic on start-up and each DNS configuration change.
When this policy is not set, or is enabled, the DNS interception checks are performed. When explicitly disabled, they're not.