How to solve the domain name failure? Step-by-step troubleshooting and repair guide

when you enter a familiar URL but jump out of the inaccessible prompt, there is a high probability of encountering the problem of unresolvable domain names, which is one of the most common types of website access failures. Whether it is a personal blog, a corporate official website or an e-commerce platform, once the domain name cannot be resolved, it will directly affect the user access experience and even cause business losses. This article will sort out a complete set of troubleshooting and repair processes for you from the local environment to the cloud configuration, and help you quickly locate the root cause of the problem and restore normal access to the website.

First, the domain name can not be resolved first check the local network environment?

many times the failure of the domain name cannot be resolved is not the domain name itself, but the problem of the local network environment, which is also the easiest part of the investigation.

1, check the local network connection status

first confirm whether the device is connected to the network normally, you can try to access other well-known websites, such as Baidu, Taobao, if these websites cannot be accessed, it means that the local network failure, rather than the domain name cannot be resolved. If other websites can be accessed normally, then focus on the resolution of the domain name itself. In addition, you can try to switch the network, such as switching from WiFi to a mobile phone hotspot, to verify whether the DNS server of the current network is abnormal and the domain name cannot be resolved.

2, refresh the local DNS cache

local device will cache DNS resolution records. When the DNS configuration of the domain name is updated, the old cache may cause the domain name to fail to be resolved. Windows users can refresh the cache by entering the ipconfig /flushdns command from the command prompt, and Mac users can enter the sudo killall -HUP mDNSResponder command at the end point. After the refresh is completed, try to access the domain name again to see if it can be resolved normally.

Second, the domain name can not be resolved to check the DNS configuration?

troubleshoot local problems, the next step is to check the DNS configuration of the domain name, which is one of the core reasons why the domain name cannot be resolved.

1, check the domain name DNS server settings

log in to the management background of the domain name registrar to check whether the DNS server address of the domain name is correct. Many users forget to update the DNS server address after changing the server or DNS service provider, resulting in the inability to resolve the domain name. If the official DNS address provided by the service provider is inconsistent, modify it in time and wait for it to take effect. The effective time of DNS modification is usually 1-24 hours. Some service providers support quick effect.

2, verify the correctness of DNS resolution records

check whether the A record, CNAME record, etc. are configured correctly in the DNS management console. A record is the Internet Protocol Address that points the domain name to the server. If the Internet Protocol Address is filled in incorrectly, it will directly cause the domain name to fail to resolve; CNAME record is to point the domain name to another domain name, to ensure that the target domain name can be resolved normally. You can use online DNS query tools, such as the DNS query function of Webmaster Tools, and enter the domain name to see if the resolution results are consistent with the configuration.

Third, the domain name can not be resolved to check the server status?

when the DNS configuration of the domain name is normal, but the domain name cannot be resolved, you need to check the running status of the server and related configurations.

1, confirm whether the server is running normally

check the running status of the server through the management background of the server provider, whether there is downtime, restart or excessive resource occupation. If the server is offline, even if the domain name resolution is configured correctly, there will be a prompt that cannot be accessed, which is easy to be mistaken for the problem that the domain name cannot be resolved. You can try to log in to the server remotely, check the system log, and troubleshoot the cause of the server failure.

2, check the server firewall settings

server firewall is set too strictly, it may intercept DNS resolution requests or website access requests, resulting in the illusion that the domain name cannot be resolved. Check whether the firewall opens common website ports such as 80, 443, and DNS-related ports 53. You can temporarily close the firewall for testing. If it can be accessed normally after closing, it means that it is a problem caused by firewall rules, and the firewall configuration needs to be adjusted.

Fourth, the domain name can not be resolved to check the status of the domain name?

the abnormal state of the domain name itself is also an important reason why the domain name cannot be resolved, which is easily ignored by users.

1, check whether the domain name has expired

log in to the domain name registrar background to check the expiration time of the domain name. If the domain name has expired, the registrar will suspend the resolution service of the domain name, resulting in the inability to resolve the domain name. Many users will forget the renewal time of the domain name, especially the managers of multiple domain names. It is recommended to turn on the domain name expiration reminder function to renew the fee in advance to avoid affecting the resolution. If the domain name has just expired, the resolution can be resumed within 1-24 hours after timely renewal.

2, check whether the domain name is locked or banned

some domain names may be locked by the registrar due to illegal use, failure to complete real-name authentication, etc., or banned by MIIT. In this case, the domain name cannot be resolved. You can check the status information of the domain name through the WHOIS query function of the domain name registrar. If the lock or abnormal status is displayed, contact the registrar in time to understand the reason and submit relevant materials to lift the restriction.

To sum up, the troubleshooting of domain names that cannot be resolved needs to be gradually advanced from the local to the cloud, first troubleshooting the local network and DNS cache, then checking the DNS configuration of the domain name and its own status, and finally checking the relevant settings of the server. Each link has a corresponding solution, as long as the process is verified one by one, the root cause of the problem can be quickly located and repaired. In daily management, it is recommended to turn on the domain name expiration reminder, regularly check the DNS configuration and server status, and prevent the failure of the domain name that cannot be resolved in advance to ensure the stable operation of the website.