Many of you will have heard about dns servers and the importance they have for the proper functioning of Internet services, but do we know what they are and what they are for? Throughout our publication we will try to answer these questions, as well as talk about some of the main dns servers that we can find today.
What are dns servers?
When we talk about dns servers we are referring to the acronym Domain Name System and it is nothing more than a software that allows us to relate an IP address, either fixed or dynamic, with the name of a domain. This greatly simplifies the process of surfing the net, as it is always easier to remember a domain name than a series of numbers associated with that name.
But in addition to being able to see the content of a given web page, DNS servers also make it easier to operate other services. For example, email or FTP access.
DNS servers
Here are some of the most commonly used DNS servers in use today. Without forgetting that we also have free DNS to use on our computers and cloud servers.
Bind
It is the most widely used DNS server in the world today. It is a distributed hierarchical database that stores domain name and IP address information. Bind 9 version is currently in use.
djbdns
In this case, djbdns is a simple set of programs that serve and resolve DNS data. It emerged as an alternative to BIND in many concepts, adding features that can be very interesting.
Designate
Designate is a multi-tenant DNSaaS service for OpenStack. It provides a REST API with integrated Keystone authentication. It can be configured to automatically generate records based on Nova and Neutron actions. Importantly, it supports a wide variety of DNS servers, including Bind9 and PowerDNS 4.
dnsmasq
It is a service that offers several functionalities, among which we can highlight: DNS server, DHCP server, PXE server and TFTP server. It is usually a very valid option for small networks where it is necessary for clients to be able to resolve names, automatically receive the network configuration or create a system to boot over the network.
In the case of the DNS server, when we ask a DNS dnsmasq server and it does not have the name resolution defined, it will ask the DNS servers that it has defined in its system and then it will save the resolution in cache. This way, in future requests the answer will come from cache.
Knot
Knot DNS is a high-performance, authority-only DNS server that supports all key DNS features, including zone transfers, dynamic updates and DNSSEC.
NSD
It is an open source DNS server program developed by NLnet Labs that is notable for functioning as an authoritative name server, i.e. it does not implement caching. It should be noted that NSD uses BIND-style zone files, as well as using information collected through zonec, a binary database file that allows for fast start-up of the NSD name service daemon.
PowerDNS
PowerDNS is a DNS server with a database (within which it supports a variety of databases, including MySQL, PostgreSQL, SQLite3, Oracle and Microsoft SQL Server, as well as LDAP) and plain text files in BIND format, as a back-end which facilitates the management of a large number of DNS entries.
Unbound
This is a recursive DNS server that acts as an intermediary between the client and the DNS servers that contain the information about the domain names. In this case, it first queries its cache, if it has the information it displays it, otherwise it queries a top-level DNS server.
Yadifa
YADIFA is a lightweight authoritative name server with DNSSEC capabilities. YADIFA was built from the ground up to address today’s DNS challenges, without compromising security, speed and stability, to deliver a better and more secure Internet experience.
