How to deal with DNS pollution? Summary of common problems and solutions

in daily network use, many people will encounter the situation that they cannot access the target website after entering the correct URL, or jump to an unfamiliar page, which is likely to encounter DNS pollution. DNS pollution will tamper with the domain name resolution results, interfere with normal network access, and cause trouble to work and Internet experience. This article will explain in detail the identification methods, incentives, solutions and protection techniques of DNS pollution to help you comprehensively deal with such network problems and restore smooth network access.

How to judge DNS pollution?

to solve the problems caused by DNS pollution, we must first accurately determine whether we have really encountered such network interference and avoid misjudging other network failures.

1, abnormal website access

if a well-known website that can be accessed normally suddenly cannot be opened, or jumps to an unfamiliar page that has nothing to do with the content of the website, or even a large number of advertising pop-ups, it may be that DNS pollution causes the domain name resolution result to be tampered with, making the request directed to the wrong server address.

2, analysis results comparison verification

can compare domain name resolution results through different devices or network environments, such as accessing the same website with mobile phone traffic. If it can be opened normally and cannot be accessed in the WiFi environment, it is highly likely that the DNS server of the WiFi network has encountered DNS pollution. You can also use online domain name resolution tools to compare whether the local resolution results are consistent with the official resolution address provided by the tool.

What are the common causes of DNS pollution?

understand the causes of DNS pollution, can help us avoid the root causes of related risks, more targeted to take protective measures.

1, malicious cyber attacks

some hackers or malicious organizations will launch DNS pollution attacks, by tampering with the cache data of the domain name resolution server, or injecting false resolution results during the transmission of the resolution request, guiding users to visit malicious websites, in order to steal users' account passwords, personal information and other sensitive data, or spread malicious programs.

2, public network environment vulnerabilities

in public WiFi environments such as shopping malls and cafes, cyber security protection measures are usually weak, and it is easy to become the hardest hit area of DNS pollution. Attackers can take advantage of the vulnerabilities of public networks to tamper with the DNS resolution configuration in the network, so that users connected to the network encounter DNS pollution, and then implement network fraud or information theft.

How to solve DNS pollution?

once it is confirmed that it has encountered DNS pollution, it is necessary to take effective solutions in a timely manner to restore normal network access functions.

1 Replacing public DNS servers

the default local DNS server may be vulnerable or contaminated, replacing it with a reliable public DNS server is a common way to solve DNS pollution. For example, domestic 114.114.114.114, Ali's 223.5.5.5, or foreign 8.8.8.8, these public DNS server security measures are perfect, which can effectively reduce the impact of DNS pollution.

2, use encrypted DNS resolution service

ordinary DNS resolution requests are transmitted in clear text, which is easy to be intercepted and tampered with, and encrypted DNS resolution services such as DNS over HTTPS and DNS over TLS will encrypt the resolution requests, so that attackers cannot easily tamper with the resolution results, and avoid DNS pollution from the transmission level.

How to prevent DNS pollution from happening again?

solve the current DNS pollution problem, it is also necessary to do a good job of daily protection to avoid encountering such network interference again and ensure long-term cyber security.

1, regularly update the network device firmware

there may be security bugs in the firmware of network devices such as routers and gateways, attackers will use these vulnerabilities to carry out DNS pollution attacks. Regularly checking and updating the firmware of the device can patch known vulnerabilities in time, improve the security protection ability of the device, and reduce the risk of being attacked.

2, carefully connect to public WiFi networks

public WiFi network is a high incidence of DNS pollution, try not to connect to unfamiliar public WiFi if necessary. If you must connect, you can turn on the firewall function of your mobile phone or computer, and avoid operations involving sensitive information such as online banking payment and account login in the public network environment to reduce the risk of information leakage.

To sum up, DNS pollution is a common network interference problem, which will seriously affect the normal network access experience. By comparing abnormal access and resolution results, it can be judged whether to encounter DNS pollution. The incentives mainly include malicious attacks and public network vulnerabilities. Replacing public DNS and using encrypted resolution services can solve the problem. Daily protection should be done by updating device firmware and carefully connecting to public WiFi, so that DNS pollution can be effectively dealt with and network access can be guaranteed.