What should I do if the domain name service DNS fails? Summary of solutions to common problems

in daily network access, DNS is the core bridge connecting domain names and Internet Protocol Addresses. Once a failure occurs, it can cause a specific website to fail to open, and it can cause the entire network to be paralyzed, which brings many inconveniences to work and life. Many users are often at a loss when encountering such problems, and do not know where to start troubleshooting and repairing. This article will sort out the common types of DNS failures in DNS, from basic troubleshooting and repair solutions to emergency skills and long-term optimization, and provide you with a comprehensive and feasible solution guide to help you quickly restore normal network access.

How to troubleshoot DNS fault causes?

want to solve the DNS fault efficiently, the first step is to accurately troubleshoot the cause of the fault, only to find the root cause of the problem, in order to carry out targeted repair work.

1, local network environment investigation

first check whether the local network is normal, you can try to access multiple different types of websites. If all of them cannot be accessed, it is most likely a local network problem; if only some websites cannot be opened, it may point to the DNS failure of the domain name service. At the same time, you can detect the connectivity of the local DNS server through the ping command. Enter "ping local DNS server IP" in the command prompt. If there is a packet loss or excessive delay, it means that the connection of the local domain name service DNS is abnormal.

2, DNS server status check

confirm whether the DNS server used by the domain name service is in normal operation, you can check through the status announcement of the service provider's official website, operation and maintenance notification and other channels. Some public DNS servers also provide special status detection pages. You can also use the nslookup command to detect the domain name resolution and enter "nslookup target domain name". If the "server failed" or "domain name cannot be found" prompt is returned, it means that the resolution function of the domain name service DNS is abnormal.

2. What are the basic repair solutions for DNS failure of domain name service?

troubleshoot the general cause of the DNS fault of the domain name service, you can try to solve the problem through some basic repair methods.

1, refresh the local DNS cache

the local DNS cache may store expired or incorrect resolution records, which can cause DNS failures in the Domain Name Service. Windows users can enter the command "ipconfig /flushdns" at the command prompt, and Mac users can enter the command "sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder" at the end point. After execution, the local cache will be emptied and the latest domain name resolution information will be retrieved.

2, change the public domain name service DNS

if it is confirmed that the DNS server itself is faulty, it can be temporarily replaced with a public DNS server, such as domestic 114.114.114.114, Ali's 223.5.5.5, foreign 8.8.8.8, etc. When replacing, just find the DNS server option in the local network settings, delete the original address and enter the new public DNS server IP. In most cases, the domain name resolution function can be quickly restored.

Third, domain name service DNS fault emergency treatment skills are what?

when the DNS failure of the domain name service causes emergency network problems, such as the inability to access the official website of the enterprise and the interruption of the business system, emergency treatment skills need to be used to restore the normal operation of the core business in a short time.

1 Temporarily modify the local hosts file

for the domain name dependent on the core business, you can directly bind the domain name and Internet Protocol Address by modifying the local hosts file to bypass the DNS resolution process of the domain name service. Add a record of "target Internet Protocol Address target domain name" in the hosts file, and save it to directly access the corresponding website. This method can ensure the temporary access requirements of the core business during the DNS failure of the domain name service, but it is only suitable for emergency processing of a small number of domain names.

2 Switch the alternate DNS server cluster

if the enterprise uses a self-built DNS cluster, multiple sets of backup DNS servers can be pre-configured. When the main cluster fails, the DNS load balancing device can quickly switch to the standby cluster to achieve seamless connection of domain name resolution services and minimize the impact of failures on business. This method is suitable for enterprise users with high network stability requirements.

How to optimize DNS to avoid recurrence?

solve the current DNS fault of domain name service, it is necessary to take a series of optimization measures to reduce the probability of fault recurrence from the root cause and ensure the long-term stability of network access.

1, configure multiple sets of redundant DNS servers

do not rely on a single group of DNS DNS servers, you can configure 2-3 groups of DNS servers of different service providers at the same time, including active, standby and emergency servers. When one group fails, the system will automatically switch to other normal servers, effectively improving the reliability of domain name resolution. At the same time, it is necessary to regularly detect the running status of these servers and update the server address in a timely manner.

2, regularly check the DNS resolution status of the domain name service

establish a regular detection mechanism and use professional DNS monitoring tools, such as DNSPod monitoring, Cloudflare monitoring, etc., to monitor the DNS resolution speed, success rate, server response time and other indicators in real time. Once abnormal fluctuations are found, timely investigation and processing. At the same time, pay attention to whether the resolution record of the domain name is correct to avoid unnecessary DNS failures caused by record configuration errors.

To sum up, the solution of DNS faults in domain name services needs to form a complete closed loop from troubleshooting, repair to optimization. First, find the cause of the failure through basic troubleshooting, and then use the corresponding plan to repair the problem. In emergency situations, emergency skills can be used to protect the core business. Finally, through optimization measures to reduce the probability of failure recurrence. Master this set of processing logic, you can calmly deal with DNS failures in the event of a domain name service DNS failure, and build a solid foundation for the stability of network access.