How to do DNS security protection? Practical protection measures and tips to share

in the link of Internet access, DNS is the key hub connecting users and target servers. Once security bugs occur, it will not only lead to user access being hijacked, jumping to malicious sites, but also may cause serious problems such as data leakage and business interruption. However, most individuals and enterprises still have a basic understanding of DNS security protection and lack of systematic protection ideas. This article will share a set of DNS security protection solutions from basic configuration to daily operation and maintenance, and then to emergency response.

, DNS security protection starts from the basic configuration?

basic configuration is the first checkpoint of DNS security protection, and it is also the most easily overlooked link. Doing this step can greatly reduce the probability of being attacked.

1, choose a secure and trusted public DNS server

avoid using the network operator's default unencrypted DNS server, prefer to support DNS over HTTPS or DNS over TLS encryption protocol public DNS, such servers can effectively prevent DNS query requests from being eavesdropped or tampered with, common Alibaba Cloud public DNS, Cloudflare DNS, etc., can choose a lower latency node according to the network environment.

2, turn off the DNS server recursive query function

if the enterprise builds its own DNS server, it is necessary to turn off unnecessary recursive query function, only allow the resolution request of the internal authorized domain name, prevent hackers from using open recursive query to launch amplification attacks, consume server bandwidth and resources, and reduce the risk of cache poisoning.

2. Advanced reinforcement measures for DNS security protection?

complete the basic configuration, it is necessary to improve the level of DNS security protection through advanced reinforcement methods to deal with more complex network attacks.

1 Deploy DNSSEC Domain Name System Security Extensions

DNSSEC verify the authenticity and integrity of DNS records through digital signature technology, which can resist DNS cache poisoning attacks from the root cause. Enterprises can contact domain name registrars to open DNSSEC services for their own domain names, and individual users can choose public DNS servers that support DNSSEC resolution to ensure that the obtained domain name resolution records have not been tampered with.

2, build DNS cache server and blacklist system

build a local DNS cache server within the enterprise, it can reduce the frequency of external inquiries and reduce the risk of exposure; at the same time configure a malicious domain name blacklist to automatically intercept known phishing and fraudulent site requests, further improve the accuracy of DNS security protection, and avoid users mistakenly visiting dangerous sites.

3. Daily operation and maintenance points of DNS security protection?

DNS safety protection is not once and for all, and daily continuous operation and maintenance can ensure the long-term effective operation of the protection system.

1, regularly update the DNS server system and software

install security patches for the system and DNS software in a timely manner to fix known vulnerabilities and prevent hackers from using public vulnerabilities to launch attacks. It is recommended to set up automatic update reminders, or conduct vulnerability scans and patch checks once a week to ensure that the software version of the DNS server is in a safe state.

2, monitoring DNS resolution requests and exception logs

real-time monitoring DNS resolution requests through log analysis tools, focusing on high-frequency abnormal queries, unfamiliar domain name requests and other behaviors. Once an abnormality is found, it can be traced back to the source for investigation. For example, a large number of requests for the same unpopular domain name in a short period of time may be implanted with malicious scripts, which need to be cleaned and intercepted immediately to ensure the dynamic effectiveness of DNS security protection.

4. Emergency response strategy for DNS security protection?

even if a full range of protection, may still encounter sudden attacks, at this time a set of perfect emergency response strategy can minimize losses.

1, quickly switch alternate DNS server

When the primary DNS server is attacked and cannot provide services normally, immediately switch to the pre-configured standby DNS server to ensure normal access to the business. The standby server needs to regularly synchronize the domain name resolution records of the primary server to avoid abnormal resolution.

2, traceability attacks and update protection rules

the end of the attack, through the log and traffic data traceability attack source and method, the attack IP, malicious domain names and other information added to the blacklist, while optimizing DNS security protection rules, such as adjusting the query request frequency limit, upgrade the encryption protocol version, to avoid similar attacks occur again.

sum up, DNS security protection is a systematic work, from the basic configuration, advanced reinforcement, daily operation and maintenance to emergency response to form a complete protection closed loop. Individual users can start from the selection of secure DNS server, enterprises need to build a multi-dimensional protection system, through continuous optimization and monitoring, effectively resist all kinds of DNS attacks, to ensure the security and reliability of network access, for daily office and business operations to build a solid network foundation defense line.