For an explanation of the round-robin configuration, please visit our tutorial here.
The DNS Failover service from DNS Made Easy is used to keep sites and web services online in the event of system or network issues. This is done by moving DNS traffic to another IP address that you have running at another location. This service can also be used to migrate traffic between redundant internet connections. A DNS Failover configuration with a round-robin will split traffic evenly between hosts unless one of the hosts is offline in which case it would be removed from the round-robin pool.
Here is how the DNS Failover services work:
DNS Failover services are configured on A records which point to IP addresses. DNS Made Easy’s monitoring nodes check your primary IP address on a 2 to 4-minute monitoring window. You can set up the monitoring servers to check if your service is running on either TCP, UDP, HTTP, or HTTPS protocols, and on any port. As soon as your primary server fails to respond from at least two different geographic monitoring locations, your DNS is instantly updated on all DNS Made Easy name servers globally to point to a secondary IP address as long as it does respond on the same port and protocol configured. You can specify up to 5 IP addresses for each of your hostnames.
Round Robin with Failover is a very common setup for organizations that uses multiple data centers and wants traffic going to all of them. This configuration would ensure that you can have the traffic spread of Round Robin while also ensuring that if one data center goes down, we will take it out of the rotation of IPs that would come up in a query. This would ensure no downtime for end-users.
1. Navigate to Managed DNS
At the top of the Control Panel, Click the DNS Menu and select Managed DNS from the drop-down.
2. Select your Domain
Select a domain from either the “Recently Updated Domains” box, or start typing the domain name in the textbox on the “Select Domain” tab.
3. Add round-robin A records (if they do not exist already)
If an A record does not already exist for the desired name, then under A Records click the plus sign (+) to add a new A record.
We will add a root record (an A record with the name field left blank) to the domain example.com with an IP address of 22.214.171.124 and a TTL of 180 seconds. If you are adding DNS Failover to an existing A record, then you will want to edit the TTL of this record to set it to a lower value. Records that use DNS Failover services should have a TTL between 180-300 seconds. Click Submit
Now, we will add a second round-robin A record with an IP address of 126.96.36.199 and a TTL of 180 seconds. At this point in the configuration, traffic to example.com is split 50/50 between 188.8.131.52 and 184.108.40.206. Click Submit
4. Add a Contact list (if it does not already exist)
Now we will set up a contact list for notification of the failover event. Select the Config menu, Click on Contact Lists
Click on the plus sign (+) to add a new contact list
Give the contact list an identifiable name and enter the email address(es) you would like included in the list, one per line. Click Submit Note: Groups are discussed in a separate tutorial here, however, if you are the only user for your account your contact list should be part of the Default group. Otherwise, it should be part of whatever group is set up to have management permissions for the domain.
5. Configure Failover
Now we set up DNS Failover.
Select the DNS Menu, select Managed DNS
Select a domain from either the Recently Updated Domains box or start typing the domain name in the textbox on the Select Domain tab
Under the SM / FO column next to the A record, click off to edit the configuration.
Enable System Monitoring and/or DNS Failover by checking the boxes. These can be used independently of one another if you wish.
These are optional:
For your information, below is the list of networks our monitoring services will check your primary IP address from: