How to operate flushdns? flushdns steps and precautions

in the process of daily use of the network, many people will encounter problems such as slow loading of web pages, failure of domain name resolution, and jumping to wrong pages when visiting websites. Many of these failures are related to abnormal DNS caching. Flushdns, as the core operation of cleaning DNS cache, can effectively solve such network problems, but many users do not know the specific operation process and precautions. This article will disassemble the operation steps of flushdns in detail for different operating systems, analyze its application scenarios, and explain the key precautions in the operation to help users easily master flushdns and quickly restore normal network access.

How to implement flushdns in different systems?

flushdns operation logic is to clean up the DNS cache records stored locally through system commands. There are differences in command entries and specific instructions of different operating systems. The following describes the operation methods of mainstream systems one by one.

1, Windows system execution flushdns

first click on the Start menu, search for the command prompt, and right-click Run as administrator to avoid flushdns operation failure due to insufficient permissions. In the open command prompt window, enter the command ipconfig /flushdns, and press the Enter key. If the prompt "Successfully refreshed DNS resolution cache" appears, it means that the flushdns operation has been completed.

2, Mac system execution flushdns

different versions of Mac system instructions are slightly different, Ventura and above versions can open the end point through the startup table, enter sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder, press the Enter key and enter the system password to complete the flushdns operation. Older versions of Mac can directly enter sudo killall -HUP mDNSResponder instructions to execute flushdns.

3, Linux system implementation flushdns

depending on the DNS service used, the instructions of flushdns are divided into two types. For systems that use the systemd-resolved service, enter sudo systemd-resolve --flush-caches to execute flushdns; for systems that use the nscd service, enter the sudo service nscd restart instruction to complete the flushdns operation.

2, which scenarios need to perform flushdns?

flushdns is not a panacea network repair operation, only in the network problem scenarios caused by DNS cache abnormalities, can play the greatest role.

1, domain name resolution failure or error with flushdns

when you enter the correct URL but prompt "can not resolve the domain name", or visit the website to jump to an unfamiliar page, the probability is that the local DNS cache record error or expired, then perform flushdns to clean up the old cache record, the system will re-request the correct resolution information to the DNS server, so as to restore normal access.

2, when the page loads slowly, you can try flushdns

if the website that can be accessed normally before suddenly loads slowly, after excluding the Internet bandwidth problem, it may be that the records in the DNS cache point to the server that is far away. After executing flushdns, the system will re-obtain the optimal server resolution address and improve the loading speed of the webpage.

3, the website needs to be flushdns

after changing the server

when the website changes the server Internet Protocol Address, the local DNS cache still stores the old IP records, which will cause users to be unable to access the website on the new server. At this time, flushdns can be executed in time to allow the system to obtain the latest resolution records and access the updated website normally.

Third, the implementation of flushdns need to pay attention to what matters?

flushdns operation itself is not harmful to the system, but if the operation is improper, it may not achieve the desired effect, and even cause short-term network fluctuations.

1, confirm the operation permission before executing flushdns

in Windows and Mac systems, administrative privileges are required to execute flushdns. If you do not obtain permission to operate directly, there will be a prompt that the instruction execution fails. Therefore, be sure to confirm that you have opened the command prompt or end point as an administrator before operation to avoid useless work.

2, flushdns need to verify the operation effect

execute flushdns, do not directly default to successful operation, you should try to visit the website that failed before to confirm whether the domain name resolution returns to normal and whether the page loading returns to normal speed. If the problem is still not solved, it may be a problem with the DNS server itself, and you need to replace the DNS server address instead of repeating flushdns.

3, avoid frequent flushdns operations

The function of

DNS cache is to reduce repeated resolution requests and improve network access efficiency. Frequent execution of flushdns will cause the system to re-resolve the domain name every time it visits the website, which will increase the waiting time for web page loading. Only when there is a clear DNS cache exception problem, flushdns operation is performed.

four, flushdns invalid how to deal with?

sometimes after implementing flushdns, the network problem persists, which requires further investigation of the root cause of the problem and other remedial measures.

1, try again after replacing the public DNS server flushdns

if the local DNS server fails, even if flushdns is executed, the system re-requests the resolution information is still abnormal, this time can be replaced by a domestic public DNS server, such as 114.114.114.114 or 223.5.5.5, after the setting is completed, flushdns is executed again, usually to solve the resolution problem.

2, check the local network settings and perform flushdns

If there is a local network setting error, such as Internet Protocol Address is set to static and does not match the network environment, flushdns alone cannot solve the problem. At this time, you should first check whether the network parameters such as Internet Protocol Address and subnet mask are correct, and then perform flushdns after fixing the setting error to ensure that the network returns to normal.

sum up, flushdns is an effective means to solve network problems caused by DNS cache abnormalities. The flushdns operation process of different operating systems is different, and users need to choose the corresponding steps according to their own system. At the same time, it is necessary to clarify the applicable scenarios of flushdns to avoid blind operation. Pay attention to permission verification and effect confirmation when executing flushdns. If flushdns is invalid, you can try to replace the DNS server or check the network settings. Master these contents, you can flexibly use flushdns to quickly solve common network resolution problems and improve the network experience.