Domain Name Server
Port 53 is utilized by the Domain Name System (DNS) to translate human-readable domain names into IP addresses. This service is crucial for the functioning of the internet, as it allows users to access websites using domain names instead of numerical IP addresses. DNS operates over both TCP and UDP protocols.
What is Domain Name Server
Port 53 is primarily associated with the Domain Name System (DNS), a hierarchical and decentralized naming system for computers, services, or other resources connected to the internet or a private network. DNS translates more readily memorized domain names to the numerical IP addresses needed for locating and identifying computer services and devices with the underlying network protocols.
DNS was introduced in 1983 by Paul Mockapetris and Jon Postel. It replaced the older system of maintaining a single file called HOSTS.TXT, which mapped names to IP addresses. The DNS system is essential for the internet's scalability, allowing millions of domain names to be resolved efficiently.
DNS operates over both TCP and UDP protocols. UDP is typically used for query and response transactions due to its lower overhead, while TCP is used for tasks requiring reliability, such as zone transfers. The DNS infrastructure is critical for the functioning of the internet, as it ensures that users can access websites and services using human-readable addresses.
Domain Name Server runs on TCP and UDP port 53 and is official IANA port.Security risk
If port 53 is open and the DNS service is running, it can be a target for various attacks such as DNS spoofing, cache poisoning, and DDoS attacks. These vulnerabilities can lead to unauthorized access, data interception, and service disruption, posing significant security risks to the network.
In our UFW tutorial you can follow instructions how you can configure UFW to close port 53. Use StackChanges to monitor if the Domain Name Server port is closed and stays closed. StackChanges will send an alert if port 53 is open again.