What should I do if the DNS server runs abnormally? Detailed reasons and handling methods

in the process of daily use of the network, many people have encountered slow loading of web pages, domain names cannot be resolved or even completely disconnected from the network. After investigation, they often find that the root cause is the abnormal operation of the DNS server. This problem may seem small, but it will directly affect office efficiency, entertainment experience, and even the normal development of important business. This article will deeply dismantle the reasons for the abnormal operation of the DNS server, and give a set of practical troubleshooting and solutions to help you quickly get rid of the network dilemma and restore a smooth network access experience.

What are the common causes of abnormal operation of DNS servers?

want to efficiently solve the abnormal problem of DNS server operation, we must first clarify the root cause of the problem, and the treatment methods corresponding to different incentives are quite different.

1, the local DNS configuration error

this is one of the common reasons for the abnormal operation of DNS servers, such as the user manually modifying the DNS address when entering the wrong IP, or the DNS address automatically obtained by the system is biased. In addition, some security software may tamper with the DNS settings without authorization when optimizing the network, resulting in the interruption of the domain name resolution link and the inability to access the webpage.

2, network service provider DNS failure

if you are using the default DNS server provided by the carrier, when the server of the service provider has a hardware failure, bandwidth overload or regional network maintenance, the DNS server will run abnormally. In this case, users using the service provider's network in the same area will usually encounter similar problems collectively, not with individual devices.

3, network environment interference or hijacking

public WiFi environment, there is a risk of DNS hijacking. Criminals guide users to visit malicious websites by tampering with DNS resolution results, which will also lead to abnormal operation of normal DNS servers. In addition, outdated router firmware and poor network line contact will also interfere with the transmission of DNS requests, causing resolution failure.

How to initially troubleshoot the abnormal operation of DNS server?

when it is suspected that the DNS server is running abnormally, do not rush to modify the settings, first narrow the scope of the problem through simple troubleshooting steps, which can greatly improve the efficiency of the solution.

1, use the Ping command to detect connectivity

press the Win + R key combination to open the running window, enter cmd to enter the command prompt, and then enter "Ping 8.8.8.8" (public DNS address), if you can receive a reply normally, indicating that the network link is through, the problem is most likely in the DNS resolution link; if there is a request timed out, it may be the fault of the network itself, rather than simply the abnormal operation of the DNS server.

2, replacement equipment verification problem range

try to access the web page with another device connected to the same network, if other devices have the same problem, it means that the root cause of the abnormal operation of the DNS server is on the network or service provider side; if only the current device has a problem, then the probability is the local device DNS settings or system failure caused.

Third, DNS server running abnormal local repair method?

If it is determined after troubleshooting that the DNS server is running abnormally caused by the local device problem, it can be repaired by the following methods.

1 Reset the local DNS cache

system will automatically cache the domain name information that has been resolved. When the cache file is damaged or expired, it will cause the DNS server to run abnormally. At this time, you can enter the "ipconfig /flushdns" command in the command prompt. After execution, the system will clear the old DNS cache and regain the latest resolution information. In many cases, network access can be quickly restored.

2, change the DNS address to public DNS

open the Network and Sharing Center, find the currently connected network, enter the property settings, double-click Internet Protocol version 4, select "Use the following DNS server address", enter the commonly used public DNS addresses in China, such as 114.114.114.114 or 223.5.5.5, these public DNS servers are more stable and can effectively avoid abnormal operation of DNS servers.

IV, DNS server running abnormal advanced solution?

if conventional methods can not solve the problem of abnormal operation of DNS servers, you need to try some advanced processing methods for more complex network environments and failure scenarios.

1, update router firmware and reset settings

router as the core transit device of the network, old firmware may lead to vulnerabilities in DNS resolution and cause abnormal operation of the DNS server. Log in to the router management background to see if there are available firmware updates. After the update is completed, restore the router to factory settings and reconfigure network parameters, which can effectively solve DNS problems caused by router failures.

2, check the network interception of security software

some antivirus software, firewalls or network optimization tools, in order to prevent DNS hijacking, DNS requests will be strictly intercepted, and sometimes the normal resolution request will be misjudged, resulting in abnormal operation of the DNS server. You can temporarily turn off the network protection function of such software, test whether the network returns to normal, and determine whether the problem is caused by the software, you can adjust the protection rules of the software and add the whitelist of DNS requests.

To sum up, abnormal operation of DNS servers is a common network problem, which is caused by local configuration, service provider failure, network environment and other aspects. When solving the problem, you can follow the idea of troubleshooting the root cause first, and then gradually dealing with it from the local to the network. First narrow the problem through the Ping command and device replacement, and then try to reset the cache and replace the public DNS. In complex scenarios, it can also be solved by updating the router firmware and adjusting the security software rules. As long as you follow this set of logic, you can quickly locate and solve the abnormal operation of DNS servers and restore stable network access.