What should I do if the DNS service fails? Summary of common problems and handling methods

in daily network use, we often encounter the situation that the network connection is normal, but the webpage cannot be opened, the loading is slow or the domain name resolution fails. This is most likely that the DNS service has failed. As the "navigator" of network access, the DNS service is responsible for converting the domain name into a recognizable Internet Protocol Address. Once there is an abnormality, it will directly affect the network experience. This article will sort out the common manifestations, troubleshooting ideas, repair methods and protection skills of DNS service failures to help you solve the problem quickly and restore smooth network access.

How to quickly troubleshoot DNS service failures?

when there is a network access exception, first confirm whether the problem is caused by the DNS service, this step can be quickly verified by a few simple operations.

1, use Internet Protocol Address direct access test

find a known public Internet Protocol Address, such as the server IP of a well-known search engine, try to enter the IP directly in the browser address bar to access the webpage. If it can be opened normally, it means that there is no problem with the network connection itself, and the root cause of the failure is most likely in the DNS service; if it is still inaccessible, it may be a problem with the network link or the server, and other links need to be further investigated.

2, with the help of ping command detection parsing

open the command prompt or end point of the computer, enter the ping command plus the commonly used domain name, and observe the return result. If the prompt that the domain name cannot be resolved appears, or the returned Internet Protocol Address is obviously abnormal, you can determine that the DNS service is faulty; if the normal IP can be returned and the delay is stable, it means that the DNS service is working normally. The problem may be in the browser settings or the website itself.

What are the common causes of DNS service failure?

understand the common causes of DNS service failures can help us locate problems more accurately and avoid blind operations.

1, the local DNS configuration error

this is one of the most common reasons for DNS service failure, such as manually setting the DNS address when entering the wrong IP, or the DNS address automatically obtained after network switching is invalid. Some users will manually change the public DNS in order to speed up network access, but if the address entered is wrong, it will cause the domain name to fail to resolve properly.

2, public DNS service node abnormal

many users use public DNS services provided by operators or third parties, when the nodes of these services are maintained, overloaded or attacked, there will be resolution delays and failures. Especially during peak network hours, some public DNS service nodes may not be able to process a large number of resolution requests in time due to excessive load.

3, local cache data exception

in order to improve the resolution efficiency, the device will automatically cache the domain name information that has been resolved. When the cached data expires, is damaged or tampered with, it will cause abnormal DNS service resolution. For example, some websites have changed the server IP, but the local cache still retains the old Internet Protocol Address, so the website cannot be accessed.

3. Specific repair operation plan for DNS service failure

determine the cause of the DNS service failure, you can take targeted repair measures to quickly restore the normal use of the network.

1, reset the local DNS configuration

if the DNS address is manually configured wrong, you can enter the network settings interface, change the DNS address to automatic acquisition, and let the operator automatically assign the available DNS service address; you can also manually replace it with a third-party public DNS service address with a good reputation, such as the commonly used public DNS address in China.

2, clean the local DNS cache data

enter the cache cleaning instruction of the corresponding system in the command prompt or end point, such as ipconfig /flushdns for Windows system and sudo killall -HUP mDNSResponder for Mac system, after execution, the abnormal DNS data of the local cache can be cleared. After cleaning, try to access the webpage again, and most DNS service failures caused by cache can be resolved.

3, switch network environment verification repair

if there is a DNS service failure when using Wi-Fi, you can try to switch to the mobile phone hotspot network to observe whether the domain name can be resolved normally. If it returns to normal after switching, it means that there is a problem with the DNS service of the original network. You can contact the operator to report the situation and request troubleshooting and repair; if it is still abnormal after switching, it may be caused by the settings or software conflicts of the device itself, and you need to further check the network-related settings of the device.

4. How to prevent DNS service failure from happening again?

solve the DNS service failure, taking some preventive measures can reduce the probability of subsequent abnormalities and improve the stability of network use.

1, configure multiple sets of alternate DNS service address

configure both the primary and alternate DNS service addresses in the network settings. When the primary DNS service fails, the device will automatically switch to the alternate address for resolution. It is recommended to choose the DNS address of different operators or service providers to avoid the situation that the domain name cannot be resolved completely due to the failure of a single service provider.

2, regularly check the DNS service resolution status

can use some network tools to regularly check the resolution speed and stability of the currently used DNS service, such as using the online DNS detection platform, enter the commonly used domain name to check whether the resolution result is normal. If you find that the resolution delay of a group of DNS services continues to be high or the resolution fails frequently, replace it with a more stable DNS service address in time.

3, install professional cyber security protection software

part of the DNS service failure is caused by malicious software tampering with the local DNS configuration, install regular cyber security protection software, open real-time protection function, can effectively prevent malicious programs to modify DNS settings, but also to intercept phishing sites false DNS resolution, to ensure the security and stability of network access.

To sum up, DNS service is a key link of network access. When a failure occurs, we can quickly troubleshoot the problem through IP access testing and ping command detection. Then, according to different incentives such as configuration errors, cache abnormalities, and node failures, we can reset the configuration, clean up the cache, switch the network, etc. Repair, and daily prevent failures by configuring alternate addresses, regular detection, and security protection. By mastering these methods, we can easily deal with DNS service abnormalities and ensure smooth network access.