What is a DNS Cache?

DNS Cache: Efficient and Sufficient

In today’s “What is” blog, we go over “What is a DNS Cache?”


Caching is how the DNS network makes retrieving information more efficient. Every time you venture onto the Internet, DNS resolutions are being made and your computer stores many of them. 

Now, anytime you go to http://www.noip.com within the cache period (typically 30 days), it will remember the IP address it remembered without having to ask for the IP address again.

We use the internet so many times throughout our day that it is easy to forget that DNS resolutions are being made, and your computer stores many of them.

How Does it Work?

Caching allows the DNS system to pull up DNS records more productively for a short time period. There are only a small number of authoritative DNS servers across the globe. Therefore, it would be easy to overload these servers or build up a lot of traffic with billions of people constantly requesting to retrieve data. But with caching DNS records in various locations, that load is much easier to manage and quicker to respond. It’s a solution that serves everyone.

TTL (Time to Live) is the amount of time that a DNS record remains cached on a DNS server. As we mentioned in a previous blog, by setting a low TTL, you can ensure that your DDNS records are updated more frequently, which can help improve the reliability of your connection.

DNS Cache Flushing

However, there will come a time when a bad entry is stored, or you notice that your computer is running much slower than usual. There are generally two ways to remove these entries. First, is to allow 24 hours to pass. Your DNS cache will clear itself out from time to time without you having to intervene. During that time, your computer will seek out and make the necessary DNS updates. Second, the more proactive approach is to flush your DNS.

Flushing your DNS cache on a regular basis is beneficial for many reasons. One of those reasons is making your computer faster.

No-IP Solutions

Managed DNS

Let’s say you have a business, and you don’t want your customers to lose connection to you or your services. With Managed DNS, you can be assured your customers will reach your website by utilizing the Managed DNS authoritative DNS servers that store your DNS records, all while providing DNS resolutions in the background. This allows your customers to reach your website, quickly and efficiently.

If your customer does not have the IP address stored in its’ computers cache, the operating system of the computer will kick off a recursive search to find the IP address for the domain that the user is trying to fetch.

Helpful Resources

Take a look at a few articles from our Knowledge Base and helpful No-IP YouTube videos that have to do with DNS cache:

How do I Flush Mac DNS Cache?

How do I Flush Mac DNS Cache YouTube video

How do I Flush Windows DNS Cache?

How do I Flush Windows DNS Cache YouTube video

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