How to troubleshoot DNS failures? Summary of practical detection and repair methods

in daily network use, we often encounter web page loading failure, domain name can not jump, network connection seems normal but can not access the site, which is likely to be caused by DNS failure. DNS as a domain name and Internet Protocol Address "translator", once there is a problem, will directly block the connection between users and network services. This article will sort out a complete set of DNS troubleshooting and resolution processes from basic detection, advanced repair to daily protection, to help you quickly locate the problem and restore the normal use of the network.

First, the basic detection method of DNS failure?

want to solve the problem of DNS failure, the first step is to accurately determine whether DNS is indeed a problem, rather than other network failures, which requires the use of basic detection methods to verify.

1, use the ping command to detect connectivity

open the command prompt of the computer, first ping a known public Internet Protocol Address, such as 8.8.8.8, if it can be connected normally, indicating that the network itself is unobstructed; then ping common domain names, such as www.baidu.com, if there is a request timed out or unable to resolve the prompt, the probability is that the DNS failure caused by domain name resolution failure.

2, use the nslookup command to parse and verify

also enter nslookup plus the target domain name in the command prompt, if the server cannot find the domain name in the returned result, or the resolved Internet Protocol Address is obviously abnormal, it can be determined that the DNS fails, resulting in a problem with the conversion process of the domain name to IP.

Second, the local repair method of DNS failure?

determine the DNS failure, you can first try to repair it from the local device. These methods are simple to operate and can solve most common DNS problems.

1, refresh the local DNS cache

system will automatically cache the resolved domain name information, when the cache error or expired, it will cause DNS failure. Enter the ipconfig /flushdns command in the command prompt, after execution, you can empty the local DNS cache, and then try to access the site again, many times it will return to normal.

2, manually change the DNS server address

if there is a problem with the default DNS server itself, it will continue to cause DNS failure. You can manually replace the DNS server address with public DNS, such as Google's 8.8.8.8, 8.8.4.4, or domestic 114.114.114.114, restart the network connection after replacement, and then test whether the domain name resolution returns to normal.

3. The advanced troubleshooting direction of DNS failure?

if the local repair method cannot solve the problem, it is necessary to enter the advanced troubleshooting process to find the root cause of the DNS failure from a wider range.

1, check the router DNS settings

many home networks automatically assign DNS addresses through routers. If the router's DNS configuration is wrong or the router itself is abnormal, it will cause DNS failures in the entire LAN. You can log in to the router management background to check whether the DNS server address is correct, manually modify it to public DNS if necessary, and restart the router for testing.

2, troubleshooting network operator DNS fault

if the network returns to normal after replacing the public DNS, it means that there is a problem with the original operator DNS. You can contact the customer service of the network operator to report the failure of DNS, confirm whether the operator's DNS server has a regional failure, and wait for the operator to repair or use the public DNS for a long time to avoid the problem.

How to avoid repeated DNS failures?

solve the current DNS failure, it is also necessary to do a good job of daily protection to reduce the probability of DNS failure and ensure the stability of network use.

1, set up multiple DNS server address

in the network settings of the device, set the primary DNS and the standby DNS server address at the same time, such as 114.114.114.114 for the primary DNS and 8.8.8.8 for the standby DNS, so that when the primary DNS fails, the device will automatically switch to the standby DNS to avoid network outages.

2, clean DNS cache regularly

can develop the habit of cleaning the local DNS cache regularly, and execute the ipconfig /flushdns command once a week or every two weeks to prevent outdated or incorrect cache data from causing DNS failures and ensure the accuracy of domain name resolution.

sum up, DNS failure is a common network problem, from basic detection to determine the root cause of the problem, to local repair to quickly solve common faults, to advanced troubleshooting to deal with complex problems, and finally through daily protection to reduce the probability of failure, this process can help us efficiently respond to all kinds of DNS failures. As long as you follow the steps to check one by one, you can quickly restore normal access to the network, and also improve your own network problem troubleshooting capabilities.