PowerDNS

PowerDNS server is a published under the GNU General Public License name server that can consult different sources for the needed information for the DNS responses. The application is written in C and can be used with all POSIX - compatible operating systems such as Linux or BSD as well as with Windows.

Special Features

PowerDNS server differs from other DNS implementations not only by the variety of data sources, also called backend, but also by its package cache. This stores the DNS responses to the last queries in a RAM cache between and sends it back for reconsideration requests for the same entry. Unlike name servers such as BIND requests are for entries in other nameservers, resolved by a separate program in the PowerDNS distribution, the Recursor.

Available backends

PowerDNS Recursor

PowerDNS Recursor is a recursive or caching -only name server, which is included both as a separate package available, as well as in the PowerDNS server source. The Recursor stands as the authoritative server under the GPL license and is already being used by several major ISPs instead of BIND resolver.

Just as the authoritative server Recursor is written and used in C - even though he is single - some functions of the Boost threading library.

Despite his determination as a caching -only name server Recursor can load code from the PowerDNS server zone files in BIND syntax and make it available in the DNS through shared use of the BIND backend.

It is possible to let the Recursor running instance behind a PowerDNS server, so that the latter initially intercept the authoritative side and then the Recursor accepts the Resolven. But it is recommended to run the Recursor free: Firstly, this is aided performance and on the other one does not run as a risk that the users get to see possibly outdated zones, which are no longer delegated in the global DNS tree.

As of version 3.1.7 allows PowerDNS Recursor embedding Lua code over which the response of the server can be manipulated both before the actual migration of the recursive DNS tree, and after receiving a NXDOMAIN response.