Why does DNS use UDP?
Today we’re going to be discussing why DNS uses UDP. One of the many reasons that it does so is due to the fact that it doesn’t have any built-in mechanisms for error checking and correction, and instead relies on lower-level protocols such as TCP or ICMP for this functionality.
The Domain Name System (DNS) provides translation between hostnames and IP addresses. It’s a critical part of Internet infrastructure, allowing users to access websites by name rather than by number. DNS servers use UDP because they don’t require an acknowledgment before providing service (like TCP), which reduces network load; while they do not provide any built-in mechanism for error checking and correction like TCP, they rely on ICMP messages in the event of errors.
Does DNS only use UDP?
No, DNS can use both UDP and TCP. For a response to be considered authoritative, it must have a resource record (RR) that uses the same protocol as is used by queries originating from within its own zone. When multiple records exist with different protocols for querying, the “most secure” one should be returned.
In other words, if a client query uses UDP, then the authoritative server must return records using UDP. However, TCP may be used to resolve those same queries from clients that prefer its use.
Difference between UDP and DNS:
UDP is a transport layer protocol in the Internet Protocol Suite. UDP provides for transmission of datagrams from one computer to applications on another computer, with no guarantee that the datagrams will arrive successfully at their destination or in order.
Domain Name System (DNS) provides translation between hostnames and IP addresses. It’s a critical part of Internet infrastructure, allowing users to access websites by name rather than by number.
Advantages of using UDP in DNS.
There are many advantages of using UDP in DNS.
- It is faster than the TCP because it isn’t concerned with acknowledgments or retransmitting any data that was lost along the way.
- The use of UDP makes it easy to implement load balancing between multiple servers for high availability and scalability purposes since each server can handle a certain amount of queries at a time.
- UDP is less reliable, but DNS doesn’t require that the data get sent successfully to its destination every single time. This means that applications can take advantage of multiple servers and network routes without having to worry about errors due to unavailable services or servers being down during high traffic periods on the Internet.
- DNS requests are very small, so they have no problems fitting into UDP segments.
Disadvantages of using UDP in DNS.
- UDP is a stateless protocol, which means that it doesn’t track connections or the status of data transmission. This also makes it harder for certain applications to use multiple servers and routes efficiently due to the lack of information about how far along each server or network route has progressed with its assigned task.
- The inability to ensure delivery results in a lack of connectivity between some clients and name servers.
- If the DNS server is under a denial-of-service attack from spoofed UDP packets, then it will be unable to respond in an efficient manner since it will be busy trying to keep track of the requests and packets that appear invalid.
- The UDP doesn’t verify if there is a valid end-point to the transmission. That means that it doesn’t guarantee anything about whether or not a DNS request reached its intended destination.
DNS has a very unique and special role on the internet. There is no other way that can substitute DNS’s functions as of now. This makes it crucial for individuals to use its services on a daily basis. DNS uses UDP because it helps reduce latency, provides better performance and more accurate responses than TCP due to not having any error control.