What is the DNS proxy within SGOS?
You want to know what DNS proxy is
The DNS proxy is useful for controlling the DNS response to specific requests. An example could be an internal reverse-proxy implementation where you need DNS to resolve to the hostname in question to the ProxySG. This would also apply to an internal HTTPS termination scenario. Users would configure their workstation DNS IP address to be that of the ProxySG. In this way, the ProxySG DNS proxy can be configured to behave similar to a hosts file. For those requests that the ProxySG is not configured to return a specific IP, it queries its own configured DNS for the resolution.
The implementation of DNS proxy doesn't necessarily have to only resolve to the ProxySG, it can also be used to override other host/domain <-> IP resolutions.
In a forward proxy environment the benefits are the DNS cache (performance, less load on actual DNS server) and to use it as a hosts file (special resolutions).
Note: The ProxySG is not a DNS server. It does not perform zone transfers, and recursive queries are forwarded to other name servers.