DNS Cache: It is known that the Internet has many secrets. It has a lot of features that are not obvious to the average user. THE access on a website, say, it may seem simple, but it's a complex, multi-step process. This process is so optimized that it takes milliseconds to complete.
But behind your computer screen, but also on other computers, a lot happens. One of them is the temporary μνήμη DNS or DNS cache.
DNS is the service linking the domain name of a page to the IP address.
DNS Package
Every page on the web has more than one easy-to-remember name. It also has an IP address, which is much harder to remember. This address "shows" the identity of the server hosting the page.
This is where the DNS service comes in. It works in the background and links an IP address with the name of the page we're writing to our browser URL to connect with.
DNS Cache
For the DNS service to work much faster, the DNS or DNS cache was created. The name gives an indication of what it does, but we will see it better.
Essentially, the DNS cache holds one record of the pages you have visited. It knows that, for example, you have visited iguru.gr and remembers to which IP address the specific domain corresponds. The DNS cache helps the DNS service not have to look up the addresses of frequently visited websites over and over again.
So when you type an address, it first checks the cache and if it is there it serves it without delay. If the address does not exist because you are visiting a page for the first time, the request will be sent to the DNS service to resolve.
The DNS cache is maintained by your operating system. But browsers also have a DNS cache. It helps them become faster. So if for example, useste Chrome and view a page, Google's browser will first check its own DNS cache.
DNS cache problems
DNS caches, especially those of browsers, may be corrupted. This can happen at any time. If the cache is not renewed for a long time, it can lead to non-downloadable web pages.
There is also DNS poisoning. It is caused by malicious web pages that import new malicious files or crash cache. What can cause this?
You want to visit Facebook, but you don't visit Facebook. DNS poisoning will get you to a page that looks like Facebook, but it's not.
So below, we'll see what you can do when the DNS cache is destroyed on your computer, or in your browser.
Delete the DNS cache
Chrome
To clear the DNS cache in Chrome, type the following in the address bar and click the 'Clear Cache' button.
chrome: // net-internals / # dns
Firefox
Open Firefox and type about: config in the address bar. Accept the warning in the box that will appear to proceed to Firefox settings. Search for:
network.dnsCacheExpiration
and set its value to zero (0).
Windows
To delete the Windows DNS cache, open a command prompt window with administrator privileges. Type the following command and press Enter.
ipconfig / flushdns
MacOS
In macOS, you should consider the version of macOS running on your computer:
macOS Yosemite and newer
sudo killall -HUP mDNSResponder
macOS 10.10 - 10.10.3
sudo discoveryutil mdnsflushcache
After entering enter the administrator password.
iOS
To delete the DNS cache on the iPhone or iPad, turn on the plane mode for 10-15 seconds. You can do this from the Settings app.
If this does not resolve any problems, just restart your device.
Android
Clean the DNS cache on Android through the browser you are using. Open the Settings app and find the apps. In the list of installed applications, select the browser you are using. On the browser details page, you'll see an entry for the amount of storage it uses. Touch it.
On the screen that shows you storage details, you will find a Clear Cache button. Touch to delete the DNS cache.
