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PowerDNS (pdns) is an open source authoritative DNS server that works as an alternative to traditional BIND (named) DNS. PowerDNS offers better performance and has minimal memory requirements. PowerDNS also works with many supporting backends ranging from simple zone files to complex database setups as well as various SQL platforms (Mysql, MariaDB, Oracle, PostgreSQL).
PowerDNS uses a separate program called PowerDNS Recursor (pdns_recursor) as the “resolving DNS server” as a standalone software package.
Authoritative and Recursor DNS Servers
Authoritative Nameservers are DNS Servers that contain the DNS records for your domains. The authoritative nameserver will answer queries with information directly from its records.
Recursor DNS servers (commonly referred to as Recursive or Resolving) function between the end user and the authoritative DNS server. Queries that are submitted by the end user arrive at the recursive DNS server first, which then searches for the records in its cache. If the queried record cannot be found in the cache, the Recursive server then sends the query to the authoritative nameserver to resolve the requested record details.
For a deeper understanding of the DNS process visit our helpful Knowledge Base article
By default, PowerDNS uses ‘Packet Cache’ to identify similar queries and then provides related answers respectively. It does this without any further processing of the request. The default cache interval is based on the TTL (time to live) setting for PowerDNS, which is 20 seconds.
In addition to caching entire packets, PowerDNS can also cache individual queries. Most DNS queries typically involve additional backend queries. An excellent example of a backend queries would be the lookup for a CNAME record.
When an end-user queries the ‘A’ record for ‘www.example.com,’ PowerDNS must first run a background query to check for the ‘www’ CNAME record. The PowerDNS Query Cache will cache these types queries for quicker recall in the event of similar future requests.
While BIND is perfectly fine for the average host or user, PowerDNS provides a robust set of features and added performance suited for larger server environments with load-balancer configurations, such as reseller. One of the critical elements of PowerDNS is that it supports DNSSEC (DNS Security Extensions) creating an extra layer of security for your domains DNS. Also, PowerDNS has a convenient web-based user interface called Poweradmin that has a variety of helpful management tools.
For a full list of notable features pertaining to the PowerDNS Authoritative Server and PowerDNS Recursor, visit the links below:
Poweradmin is a browser-based administration tool for PowerDNS. It supports master, native and slave zones types. It can also be used for automatic provisioning and supports multiple coding languages. Below are a few examples of what the Poweradmin interface looks like and the tools and features it possesses. For a full list of Poweradmin features visit https://www.poweradmin.org/features.html.
Main Page — Available tools and features can be seen on the main page of Poweradmin when you first log in.
Search Tool — Utilizing the search tool allows you to query all the DNS zone setups with your PowerDNS for a specific string of text (name, IP address, etc.)
Add a Master Zone — The Master Zone is used as the primary point of a query for all DNS requests made to the PowerDNS.
— As a fail-safe, the secondary zone handles DNS queries should the Master Zone experience issues or go unresponsive.