DNS Monitoring 101 – Verify DNS Mapping

This Tip of the Day is the first in a three-part series on Domain Name System (DNS) monitoring. The Domain Name System is often described as “the phonebook of the Internet.” While humans access the Internet via domain names such as npr.org or bbc.com, web browsers interact via Internet Protocol (IP) addresses. DNS translates domain names to IP addresses so that browsers know which Internet resources to load.

There’s a lot to talk about in relation to DNS Monitoring, hence the three parts in this series. After all, DNS is the first way in which users encounter your brand. Arguably, it’s the most important element of web performance to monitor. If DNS infrastructure goes down, all the digital services that rely on it go down too.

Today’s Tip: Ensure Users are Served by the Correct DNS Server

Today’s Tip focuses on a DNS component that has a major impact on user performance: making sure users are being served by the correct DNS server.

What does the DNS server do? It is responsible for resolving the domain name and getting its IP address. Each one stores a database of names and IP addresses. There are many DNS servers across the Internet. If one DNS server is not able to find an associated IP address, it will forward the request to another DNS server, continuing until the client is able to find the specified IP address.

Many companies outsource their DNS service to a third-party provider with a globally distributed network. The goal is to keep latency as low as possible by having your DNS resolve as physically close to your user’s location as possible. If you have an end user in Singapore, for instance, but the DNS server is in Amsterdam, your traffic will have to travel 13,000 miles in a round trip and via multiple hops. Imagine the additional latency that is introduced into the DNS lookup and resolution process simply by having your DNS server in the wrong place.

Monitor DNS Servers to Ensure Reachability

Monitoring DNS servers allows DevOps teams to ensure reachability of their digital services by detecting issues with their DNS provider(s) and either switch to the backup provider (if redundancy is set up) or work with the vendor to re-route traffic to different resolvers and/or name servers.

Catchpoint has two types of DNS monitoring tests:

DNS Direct

The DNS Direct test isolates each name server to measure the time it takes each one to query and get an answer from a domain. It also ensures the accuracy of responses.

DNS Experience

The DNS Experience test measures the time it takes to resolve a domain by running a recursive DNS query. Catchpoint randomly selects a server from each level of a DNS route and queries it for the domain, allowing you to get a complete picture of how your DNS was resolved.

Both tests can help you identify what went wrong and why, both in terms of performance and alerting you to potential DDoS attacks, DNS hijacks, and DNS cache poisoning.

Today’s Video: Work Smarter, Not Harder

In today’s video, you will:

• Understand how Catchpoint’s DNS monitoring service can help ensure your users are being serviced by the correct DNS server through a concrete example in the Catchpoint portal;
• Hear about the latency challenges introduced when the wrong DNS server is being used;
• Get familiar with a tool that can be used to check the location of IPs around the world;
• Find out more about how to use Catchpoint’s two types of DNS monitors: Direct and Experience;
• Learn how to set up alerts and notifications for specific DNS issues.

Utilizing DNS monitoring in all its aspects will help keep your end users happier, and hopefully allow you to work smarter, not harder.