Validating identity to router
Originally written for Posix-compatible Unix-like operating system, Unbound currently runs on Free BSD, Open BSD, Net BSD, and Linux, as well as Microsoft Windows.
Then you can decide what type of DNS server you want and go right to the configurations below.
Most modern operating systems have prebuilt packages (rpm, deb, tgz).
You can always install Unbound from source if you want to.
Caching name servers store DNS query results for a period of time determined in the configuration (time-to-live) of the domain name record in question.
Recursive name servers resolve any query they receive, even if they are not authoritative for the question being asked, by consulting the server or servers that are authoritative for the query.