Whether you are hosting your website on your own server or with a web hosting service, proper functionality of Domain Name System (DNS) is essential for ensuring uptime and performance of your website. Even if your entire web server infrastructure is working fine, a tricky DNS problem can result in an unresponsive site. Thus, it is important to include DNS monitoring in your website monitoring strategy to protect your online presence as well as to enhance end-user experience.
Role of DNS:
DNS is responsible for translating an easy-to-remember website name into its respective IP address of the web server that hosts the site. When a user requests for your website by typing its name in the browser, the DNS infrastructure points it to the address of the web server. If the site is hosted in multiple locations, it will point to the one closest to the requesting user. Once the browser has the IP address of the web server, it will then issue an HTTP request for the web page. Thus, you can see how DNS is crucial in making your website reach your customer.
DNS related issues – what may go wrong:
DNS configuration and resolution is often complex and tricky. Since a DNS resolution includes a series of steps, a problem during any of the steps can fail the entire process.
•Unavailability of DNS server: The DNS server is like any other technological infrastructure that may go down due to scheduled or unscheduled outages. When the DNS server serving information about your website goes down, the client will be unable to get details of your web server to issue an HTTP request.
•Improper DNS configuration: Improper configuration of a DNS server can occur during initial set up of the domain, or later as needs change and configuration changes become necessary. You may have heard about sites not working for users from specific locations. This is the result of erroneous DNS configuration where the DNS servers will not return IP addresses for requests coming from impacted areas. Other configuration errors may result in lost e-mail or complete inaccessibility of the site.
•Latency in DNS resolution: Latency results in slow loading of the site, though your web hosting infrastructure is working perfectly. If a request cannot be served from DNS cache, it has to recursively query other nameservers, resulting in latency. Overload of a DNS server can also result in latency of DNS requests.
•DNS cache poisoning: Local DNS resolvers with less security can often fall prey to an attacker who can insert a fake address record for your domain name into the DNS. Using this, the attacker can tamper with cache records of the resolver to point your domain name to a phishing site. Such attacks are difficult to detect, especially from data centers.