What is Round Robin DNS?
Round Robin DNS (domain name server) is a creative way to lighten the server and bandwidth requirements of hosting websites by using a series of IP addresses. This technique is particularly useful to companies whose websites get a very large number of hits and/or a large number of bandwidth-consuming downloads. Through a careful series of protocols, companies implement Round Robin DNS by assigning a set number of IP addresses to rotate the responsibility of allowing website users to access the company’s website. Think of these IP addresses as A, B, C, and D. When the first user accesses the website, Round Robin DNS takes the user to address A. The second user gets taken to address B, and so on. Once A is used, it goes to the back of the line; so the fifth user accesses address A. The name of the protocol is just a clue as to what actually happens, however. Despite the sequential nature of the example, the IP addresses are not assigned in sequential order. Rather, they get assigned in r
Round robin DNS is a method by which a DNS record has more than one value. When a request is made to the DNS server which serves this record, the answer it gives alternates for each request. For instance, if you had a two webserver that you wished to distribute requests between, you could setup your DNS zone thusly: www IN A 1.2.3.4 IN A 2.3.4.5 When a query is made to the DNS server it will first give the IP of 1.2.3.4 for the www host. The next time a request is made for the IP of www, it will serve 2.3.4.5. This will alternate back and forth on each subsequent query. While this is a form of load balancing, it should be noted that if one of the hosts becomes unavailable, the DNS server does not know this, and will still continue to give out the IP of the downed server.
A. A load balancing technique in which balance power is placed in the DNS server instead of a strictly dedicated machine as other load techniques do. Round robin works on a rotating basis in that server IP address is handed out in rotation. To setup Round Roubin DNS at dnsExit, you can simply assign multiple IP addresses to the same host/subdomain. For example: • www.yourdomain.com 23.22.28.1 • www.yourdomain.com 23.22.28.2 • www.yourdomain.com 23.22.28.3 In the above, each IP each gets 33.3% of the queries. If you want more hits to IP 23.22.28.2, you can add one more entry of www to that IP so that 50% of the query will go to 23.22.28.2 and the other 2 IPs will each get 25% of the queries.
