Best Public DNS Servers

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Global DNS Server Validation System

For global network service deployment, DNS server availability directly impacts service quality. We developed a Bash-based automated validation system to: relevant explanation

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How CDN Implements DNS-Based Scheduling

    CDN (Content Delivery Network) caches content on edge nodes close to users to accelerate access speed and reduce the load on the origin server. Scheduling refers to the process of deciding which node a user’s request should be directed to.

    DNS is the most common scheduling method. DNS-based scheduling works by resolving the same domain name to different IP addresses, so that different users are directed to different CDN nodes.

    Since a CDN cannot directly obtain the end user’s IP address, it can only see the IP of the LDNS (Local DNS Server) that initiates the DNS query. Therefore, the scheduling logic is based on the LDNS IP:

    1. The CDN collects a large amount of data about LDNS IPs, such as geographic location, ISP, and quality metrics
    2. It maps LDNS IPs to corresponding regions or ISPs.
    3. Based on this information, the CDN selects the optimal edge node and returns its IP address to the user.

What is DNS?

    The Domain Name System (DNS) is a phone book for the internet, a framework which translates domain names, like facebook.com or twitter.com, into the IP addresses necessary for devices to load those internet resources (e.g. 9.9.9.9). In geek terms, that's called Resolution.

    The mechanics of DNS can be quite complicated, as information isn't held in a single database, but rather distributed in a worldwide directory including a vast number of DNS servers.

    Fortunately, the average internet user doesn't have to get involved in the low-level technical details. Your ISP automatically provides you with a DNS server whenever you go online, and when you enter a URL into your browser, this finds the relevant IP address for you.

How can I find the fastest DNS service?

    DNS speed depends on many factors, including your location, the distance to your nearest server, and that server having enough power and bandwidth to handle all the queries it receives.

    DNS Jumper is a portable freeware tool which tests multiple public DNS services to find out which delivers the best performance for you.

    The program has a lot of options, but isn't difficult to use. Launch it, click Fastest DNS > Start DNS Test, and within a few seconds you'll be looking at a list of DNS services sorted by speed.

    DNS Jumper can be useful, in particular because it's checking how servers perform from your location, but it doesn't run enough tests over a long enough period to give you a definitive answer.

How can I find the fastest DNS service?

    DNS servers can vary hugely in speed, particularly in areas which don't always have the best internet coverage (Africa, South America, Oceania.) To take an example of a single day when we tested, DNSPerf.com reported Cloudflare achieved an average 4.43ms query time for Oceania, while Yandex was left trailing at 350.24ms. That's potentially more than a third of a second in extra waiting time before your browser can access any new website.

    This is an extreme example, to be fair. European or US lookups may see less than 30ms variation between most DNS services, and as your device or router will probably cache the address for reuse later, even this delay will only occur very occasionally. Still, a sluggish DNS server can noticeably slow down your browsing in some situations, and trying an alternative – especially as there are multiple options that are all free is often a good idea.

    There's a second possible benefit in terms of uptime. If and when your ISP DNS server fails, you will encounter some difficulty accessing some or all of your favorite sites. Big-name providers such as OpenDNS claim they've had 100% uptime going back years. These are the factors we take into consideration when choosing the best DNS servers.