A DNS server, short for Domain Name System server, is a crucial component of the internet infrastructure that translates human-readable domain names into machine-readable IP addresses. In simpler terms, it helps your Mac (or any device) to find and connect to websites by translating the URL you type into the browser into the IP address of the website’s server.
How Does DNS Work?
When you enter a URL like “www.example.com” in your web browser, your Mac sends a DNS query to a DNS server. This query asks for the IP address associated with the domain name. The DNS server then checks its records or forwards the request to other DNS servers until it finds the correct IP address.
Once your Mac receives the IP address from the DNS server, it can establish a connection with the webserver hosting the website you requested. This whole process happens behind-the-scenes and is usually completed within milliseconds.
Configuring DNS Servers on Your Mac
Your Mac typically uses your Internet Service Provider’s (ISP) default DNS servers. However, you can configure custom DNS servers on your Mac for various reasons such as improving speed, bypassing restrictions, or enhancing privacy.
To configure DNS servers on your Mac:
- Open System Preferences: Click on the Apple menu in the top-left corner of your screen and select “System Preferences”.
- Select Network: In System Preferences, click on “Network”.
- Select Your Network Connection: Select your active network connection from the list on the left side of the Network preferences window.
- Click on Advanced: Click on “Advanced” in the lower-right corner of the Network preferences window.
- Go to the DNS tab: In the Advanced settings, navigate to the “DNS” tab.
- Add or Remove DNS Servers: To add a new DNS server, click on the “+” button and enter the IP address. To remove a DNS server, select it and click on the “-” button.
- Arranging DNS Servers: You can arrange the order of your DNS servers by dragging and dropping them in the list. The Mac queries them in order until it finds a response.
- Click OK: Once you have configured your desired DNS servers, click on “OK” to save the changes.
Note: It’s recommended to note down your original DNS server settings before making any changes so that you can revert back if needed.
DNS Cache
Your Mac maintains a cache of recently resolved domain names and their corresponding IP addresses. This cache helps to speed up future requests by eliminating the need for repeated DNS lookups. However, sometimes this cache can become outdated or corrupted, leading to issues like website not loading or being redirected to incorrect websites.
To clear your Mac’s DNS cache:
- Open Terminal: Launch the Terminal application. You can find it in Applications > Utilities > Terminal or by searching for “Terminal” using Spotlight (Cmd + Space).
- Type Command: In the Terminal window, type “dscacheutil -flushcache” and press Enter.
- Flush Cache: The command flushes your Mac’s DNS cache, and you should see a confirmation message.
After clearing the DNS cache, your Mac will rebuild it with fresh DNS information as you browse the web.
Conclusion
A DNS server plays a vital role in translating domain names to IP addresses, enabling your Mac to connect to websites. By understanding how DNS works and configuring custom DNS servers when necessary, you can enhance your internet experience in terms of speed, privacy, and accessibility.