How can I configure how long the DNS cache stores positive and negative responses? (2024)

FAQs

How long is DNS cache stored? ›

The default setting is one day (86,400 seconds).

To enable DNS caching on your web server, you'll need to install the software on your web server, edit the configuration file to specify the parameters for the cache, restart the DNS caching service and test its functionality, and then configure your web server to use the local DNS cache as the primary DNS resolver.

Negative caching" - the storage of knowledge that something does not exist. We can store the knowledge that a record has a particular value. We can also do the reverse, that is, to store the knowledge that a record does not exist.

DNS TTL (time to live) is a setting that tells the DNS resolver how long to cache a query before requesting a new one. The information gathered is then stored in the cache of the recursive or local resolver for the TTL before it reaches back out to collect new, updated details.

To display the contents of the DNS resolver cache: Type ipconfig /displaydns and press Enter. Observe the contents of the DNS resolver cache.

In normal circ*mstances, the TTL for a DNS zone plus its Refresh interval should give you the maximum time it will take for all DNS servers to get the latest information. Generally, that's a lot less than 24-48 hours.

Can DNS caching be disabled? While possible, disabling it is generally not recommended, as it may lead to slower internet speeds and increased server load.

Navigate to All Programs > Accessories and select Command Prompt. In the command line interface, run ipconfig /flushdns . You should receive a confirmation message once the DNS cache is flushed.

How do I fix DNS cache error? ›

Clear the cache

From the command prompt you can type ipconfig/flushdns and this will make sure nothing stored in the DNS cache is causing problems, and the next time you try the website, it will be forced to download new DNS information.

You can configure the TTL value from 0 to 604,800 seconds. You can also configure the TTL value for cached negative responses. Negative caching is the storing of the record that a value does not exist. In this example, you set the maximum TTL value for cached (and negative cached) responses to 86,400 seconds.

Generally, we recommend a TTL of 24 hours (86,400 seconds). However, if you are planning to make DNS changes, you should lower the TTL to 5 minutes (300 seconds) at least 24 hours in advance of making the changes.

Use long caching times

We recommend setting the cache time of page resources to at least 24 hours.

By default, Windows stores positive responses in the DNS cache for 86,400 seconds (i.e., 1 day) and stores negative responses for 300 seconds (5 minutes).

Records in the cache are kept for their TTL, then re-queried. The TTL was defined in SOA record of specific zone in DNS server. If you need clear DNS cache from client side for every 15 minutes, it is OK. After these caches were cleared, if needed, the client will re-query these records from DNS server.

It's important to understand that your DNS cache will clear itself out from time to time without your intervention. That's because the DNS cache — in addition to saving all information that's relevant to identifying and finding a website — also saves a component called TTL, or time to live.

DNS cache is temporary storage on a browser or device's OS used to store the data about previous DNS requests from that device or browser.

It will not clear anything other than your DNS cache, hence everything else will be where it was (passwords, auto-fill, etc). The purpose of DNS is to resolve hostnames (such as google.com) and convert it to its IP address (172.217. 12.46 in my case). Your cache will simply repopulate itself once you revisit a website.