How to use the DNS cache command? Zero-based operation guide

in daily network use, occasionally encounter problems such as domain name resolution failure and abnormal web page loading, which is most likely related to DNS caching. DNS caching can improve the efficiency of domain name resolution, but expired or wrong caching will cause network failures. At this time, DNS cache commands need to be used to intervene. This article will explain in detail the DNS cache command operations under different operating systems from a zero-based perspective, including pre-execution preparation, specific steps, verification methods and common problem troubleshooting, to help beginners easily solve DNS cache-related network problems.

What preparations should be done before the DNS cache command is executed?

before using DNS caching commands, be well prepared to avoid operational errors and ensure smooth execution of commands.

1 Confirm the current network status

first test whether the current network can resolve the domain name normally by pinging common domain names such as baidu.com, and record the resolution results, which is convenient for comparison with the results after executing the DNS cache command. If the network connection itself is interrupted, fix the network problem first and then operate the DNS cache command.

2, get system admin permission

most DNS cache commands require administrator privileges to execute, Windows users need to right-click Command Prompt or PowerShell to select Run as administrator; Mac and Linux users need to prefix the command with sudo and enter the administrator password to execute the relevant DNS cache command.

Second, the DNS cache command operation steps of different systems?

different operating systems DNS cache storage locations and management methods are different, the corresponding DNS cache commands are also different, the following explains the operation methods of the three mainstream systems.

1, Windows system DNS cache command

Windows users can use the command prompt or PowerShell to execute DNS caching commands. First open the tool as an administrator, enter ipconfig /flushdns and press Enter, the system will prompt you to successfully refresh the DNS resolution cache. To view the current DNS cache content, enter ipconfig /displaydns, the interface will list all cached domain name resolution records, including domain name, record type, lifetime and other information.

2, the DNS cache command of the Mac system

Mac different versions of DNS cache commands are slightly different. Ventura and above, open end point and enter sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder and press Enter, enter the password to complete DNS cache refresh. Older versions such as Catalina use sudo killall -HUP mDNSResponder. After execution, end point does not prompt to indicate that the DNS cache command is executed successfully.

3, Linux system DNS cache command

Linux system's DNS cache service is usually systemd-resolved or nscd, and the default service is different for different distributions. For systems using systemd-resolved, enter sudo systemctl restart systemd-resolved to restart the service to refresh the cache; for systems using nscd, enter sudo systemctl restart nscd to complete the execution of the DNS cache command by restarting the service.

How to verify the effect after the DNS cache command is executed?

execute the DNS cache command, you need to verify that the operation is in effect to ensure that the DNS cache has been flushed or viewed correctly.

1, retest domain name resolution

ping the domain name tested before again, compare the resolution IP before and after executing the DNS cache command. If the previous resolution is the wrong IP, resolve to the correct IP after execution, indicating that the DNS cache command takes effect; if the previous resolution is slow and the resolution speed improves after execution, it can also prove that the DNS cache command has played a role.

2 View DNS cache content

Windows users can re-enter the ipconfig /displaydns to see if the cache content is empty or updated; Mac users enter dscacheutil -q host to view the current cached domain name resolution record; Linux users enter systemd-resolve --statistics to view cache statistics according to the service they use, to confirm the execution effect of the DNS cache command.

four, DNS cache command common problems how to troubleshoot?

may encounter problems such as execution failure and no effect when using DNS cache commands, mastering troubleshooting methods can quickly solve the fault.

1, command execution prompt permission is insufficient

Windows users check if they are running the command tool as an administrator, Mac and Linux users confirm that the sudo prefix is added before the command and the administrator password is entered correctly. After regaining administrator privileges, execute the DNS cache command again.

2, the domain name resolution is still abnormal

if the domain name resolution is still abnormal after executing the DNS cache command, first check whether the local DNS server settings are correct, you can try to switch to public DNS such as 114.114.114.114 or 8.8.8.8, and then re-execute the DNS cache command. If the problem persists, it may be the resolution failure of the domain name itself, you can confirm the global resolution status of the domain name through the online DNS query tool.

to sum up, DNS cache command is a practical tool to solve DNS cache related network problems. This article comprehensively explains the use of DNS cache command from preparation work, different system operations, effect verification to problem troubleshooting. Novices only need to follow the steps to easily master the DNS cache command of Windows, Mac, Linux systems, quickly solve network problems such as abnormal domain name resolution and slow web page loading, and improve network experience.