How to deal with the domain name that cannot be resolved? Detailed troubleshooting and repair steps guide

in the process of website operation, the domain name cannot be resolved is one of the common failures. It will cause users to be unable to access the website normally, directly affecting the traffic, user experience and even business conversion of the website. Many webmasters will be at a loss when encountering the problem of domain name cannot be resolved and do not know where to start. This article will sort out a complete set of domain name cannot be resolved troubleshooting and repair processes for you from basic detection, configuration verification, service verification and other levels to help you quickly locate the problem and solve the fault, so that the website can return to normal access status as soon as possible.

First, the basic detection method of domain name can not be resolved?

encounter the problem that the domain name cannot be resolved, the first thing to do is to confirm the scope of the problem through basic detection, determine whether it is a local fault or a global fault, and narrow the scope for subsequent investigation.

1, use the ping command to detect connectivity

enter the command to ping the domain name in the command prompt or end point of the computer, if the "request timed out" or "host cannot be found" prompt is returned, it can basically confirm that there is a problem that the domain name cannot be resolved. At the same time, you can try to ping other normal domain names, and compare the results to determine whether it is a single domain name problem or a local network problem.

2, parse the query with the nslookup tool

nslookup is a tool specially used for DNS query. After entering the nslookup domain name instruction, if the error prompt other than "non-authoritative response" is returned, such as "server failed" "domain name not found", etc., it means that the problem that the domain name cannot be resolved is at the DNS level, and the DNS configuration needs to be further checked.

2, the domain name can not be resolved configuration verification points?

eliminate the basic network problems, the next step is to focus on checking the configuration information of the domain name itself, which is one of the common reasons why the domain name cannot be resolved.

1, check whether the domain name registration status is normal

log in to the background of the domain name registrar to check the registration status of the domain name. If the domain name is in the state of expiration, lock or redemption, it will directly lead to the failure of the domain name to be resolved. If the domain name expires, the renewal operation needs to be completed in time. The resolution function can be restored within 1-2 hours after the renewal; if it is locked, you need to contact the registrar to unlock it.

2, check the DNS server address configuration

check whether the DNS server address is correct in the background of the domain name registrar. Many domain names cannot be resolved because the DNS server address is misconfigured or not effective. If you have just modified the DNS server address, you need to wait for the global effective time of 12-24 hours. During this period, the domain name in some areas may not be resolved.

3 Confirm compliance of parsing record settings

check whether the A record, CNAME record and other resolution records of the domain name are correct, such as whether the A record points to the correct server Internet Protocol Address, and whether the CNAME record points to a valid domain name. If the resolution record format is wrong and the Internet Protocol Address is filled in incorrectly, the domain name cannot be resolved. After modification, you also need to wait for the effective time.

3. DNS service verification that the domain name cannot be resolved?

if there is no abnormality in the domain name configuration information, it may be a problem at the DNS service level, and a comprehensive verification of the DNS service is required.

1, check whether the local DNS cache is abnormal

the DNS cache of the local computer may fail to resolve the domain name due to cache expiration or wrong data. At this time, you can enter the ipconfig/flushdns instruction from the command prompt to clear the local DNS cache, and then try to resolve the domain name again to see if it can return to normal.

2 Replacement of public DNS server test

If you use the DNS server of the local network operator, the domain name may not be resolved due to server failure or cache problems. You can try to replace the local DNS server address with public DNS, such as 114.114.114.114 or 8.8.8.8, and then re-check the domain name resolution to determine whether it is the problem of the original DNS server.

4. The advanced investigation direction of domain name unresolvable?

after the previous investigation, if the domain name cannot be resolved, it is necessary to find the root cause of the fault from a deeper level.

1, check whether the domain name is blocked or blocked

some domain names may be intercepted by network regulatory authorities due to content violations or other reasons, resulting in domain name resolution problems in domestic areas. You can try to resolve the domain name through overseas servers or proxy tools. If it can be resolved normally overseas and not in China, it is likely that the domain name will be intercepted, and you need to contact the relevant departments to appeal.

2, verify whether the server network is normal

even if the domain name resolution is normal, if the server itself has network failures, downtime and other problems, it will make users mistakenly think that the domain name cannot be resolved. You can connect to the server remotely or contact the server provider to confirm the network status and running status of the server. If the server fails, you need to solve the server problem before verifying the domain name resolution.

To sum up, solving the problem of domain name unresolvable needs to follow the investigation process from basic to advanced, first confirm the problem scope through basic detection, then check the domain name configuration and DNS service, and finally dig the root cause from the advanced direction. As long as you follow this process to gradually investigate, you can quickly locate the fault point of domain name unresolvable, efficiently complete the repair work, and ensure the normal access of the website. Webmasters should also regularly check the domain name status and resolution configuration to avoid the latent risk of domain name unresolvable in advance.