DNS 101: How to Verify DNS Mapping

Performance & Operations

Have you ever wanted to check your DNS server mapping to verify recently-pushed changes are routing your users to the correct destination? In this article, we’ll take a look at how to do exactly that. But first, if you’re new to DNS concepts, it’s worth reading our in-depth DNS monitoring guide to familiarize yourself with all of the components that make up and interact with the DNS.

Why DNS Mapping Matters

As a quick reminder, DNS server mapping is important for your end users because inaccurate user-to-server mapping can greatly impact their digital experience, presenting as “slowness.” Resolution times are affected by the distance between an end user and the DNS server assigned to them. A user in Boston, for example, should not be assigned to a DNS server in Los Angeles.

Ways to Verify DNS Mapping with Catchpoint

There are two main ways you can verify your DNS Mapping with Catchpoint:

  • Direct Monitoring: Isolates each name server and measures the time delta between a DNS query and the domain’s answer. With Direct Monitoring, you can monitor the speed of a domain lookup on a specific DNS server. This type of monitoring can be ideal for smaller implementations or tracking the performance of a single server.
  • Experience Monitoring: Measures resolution time by emulating a DNS server query from each level of a DNS route. With Experience Monitoring, you can better understand the full resolution chain of a given domain. Domains with heavy loads rely on multiple DNS servers to locally serve different geographies and protect against server failure. The scope of DNS resolution expands once you consider that a web page may depend on multiple domains to load javascript libraries or images from various repositories. This type of monitoring is ideal for larger implementations and checking for the overall experience of going through a chain of DNS resolution.

How to Verify DNS Mapping

In Catchpoint’s platform, perform the steps outlined in this section alongside our video tutorial:

  1. Choose a Test type.
  2. Select a Query type (e.g., A IPV4 Address).
  3. Label your test.
  4. Define Test Targets (e.g., last mile).
  5. Choose a run frequency.
  6. Set up an alert.
    a. Go to IPInfoDB.com
    b. Find the recommended IP address for the segment of users this test should cover.
    c. Set a condition for your alert to trigger when an IP address does not match the recommended IP address provided.
  7. Navigate to your test’s alerts.
  8. Grab the Host IP address from a relevant alert.
  9. Search for the Host IP address on IPInfoDB.com to discover its location.

Conclusion

Now you know how to check your DNS server mapping using the Catchpoint platform. Are you looking for more DNS-related tips? Check the second part of our three-part series on how to guard against DNS attacks.

Published on
Jun 23, 2020
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updated on
September 20, 2021
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