Round-robin DNS is a technique used to distribute network traffic across multiple servers in a balanced manner. It is a method of load balancing that spreads incoming requests across a set of servers by rotating the order in which they are accessed.

Here’s how round-robin DNS works:

1. Multiple servers are set up with the same domain name (e.g., server1.example.com, server2.example.com, server3.example.com).

2. A DNS server is configured to respond to DNS queries for the domain name with multiple IP addresses, each corresponding to one of the servers. These IP addresses are typically returned in a different order for each DNS query.

3. When a client makes a request to the domain name, the client’s DNS resolver randomly selects one of the IP addresses returned by the DNS server.

4. The client then connects to the selected server using the chosen IP address to complete its request.

5. Subsequent requests from the client or other clients may receive different IP addresses in a different order, and the process repeats.

The round-robin DNS technique allows for the distribution of incoming requests among multiple servers, ensuring a more balanced workload across the infrastructure. It can be useful for load balancing, increasing fault tolerance, and improving overall system performance.

However, round-robin DNS has some limitations. It does not consider the current load or availability of servers, so it may direct traffic to a server that is heavily loaded or experiencing issues. Additionally, it doesn’t provide session persistence, meaning subsequent requests from the same client may be directed to different servers, which can cause issues with stateful applications. To address these limitations, more advanced load balancing techniques like dynamic DNS updates or dedicated load balancers are often used.