Failover Group Creation

Key information:

• The name assigned to a failover group must be unique.
• A group can failover either CNAME or address records, but not to both.

• Although a group can contain a set of IP addresses for each version (i.e., IPv4 and IPv6), traffic is segregated and load balanced according to the IP version used by the network through which the request was received.

  • In a load balancing group that contains both IP versions (i.e., IPv4 and IPv6), a server's weight only affects traffic distribution for servers of the same IP version.
  • A group must contain at least two IP addresses of the same version (i.e., IPv4 or IPv6).
• A health check configuration should be added to each IP address/CNAME to ensure that traffic is redirected when a server/domain can no longer properly serve traffic.

• The speed at which traffic can be completely pulled from an unhealthy server/domain is affected by the length of the failover group's TTL. TTL configuration varies according to the type of DNS configuration being performed.

  • Primary Zone: A failover group's TTL must be defined upon creation. Consider setting a short TTL (e.g., 300 seconds) on a failover group to ensure that traffic is pulled in a timely manner.
  • CNAME & Subdomain Delegation: The TTL for all failover groups is 300 seconds. This setting cannot be modified.

• A failover group will not be created until Submit Group is clicked.

The procedure through which a failover group can be created varies by the method used to direct DNS traffic. Instructions for each method are provided below.

To create a failover group (Primary Zone)

1. Make sure that the desired zone has already been created.

   Learn more.

2. Make sure that the desired address or CNAME records (i.e., A, AAAA, or CNAME) have been created in that zone.
3. Click Create LB/FO.
4. Click Create Failover.
5. Mark either two address or CNAME records.
6. Click Finish creating FO. A dialog box will appear.
7. In the Name option, define the subdomain for the failover group.
8. In the TTL option, define the number of seconds that the records associated with this group should remain cached.
9. Click Add.
10. Click "Edit" corresponding to the IP address or CNAME that should be the primary server.
11. Make sure that the check box in the Primary column is marked.
12. The Add HC button provides the means through which a health check configuration can be created.
    Learn more.
13. Click "Edit" corresponding to the IP address or CNAME that should be the backup server.

14. Make sure that the check box in the Primary column is cleared.

15. The Add HC button provides the means through which a health check configuration can be created.
    Learn more.

16. Click Done.
17. Click Submit Group to save your changes.

Creating a failover group will overwrite the name and TTL assigned to the records associated with it. If this is undesired, you may need to create additional address records. Keep in mind that you can create multiple records that point to the same IP address/domain.

To create a failover group (CNAME Record/Subdomain Delegation)

1. Navigate to the Route (DNS) page.
2. Click Add New.
3. In the Type option, select "Failover."

4. In the Name option, type the desired hostname (e.g., www). Additional information is provided below:

   • CNAME Record: A system-defined domain (e.g., www.0001.edgecastdns.net) will be generated from the specified hostname.
   • Subdomain Delegation: The name assigned to the failover group should match the subdomain delegation (e.g., ftp.widgets.com).

5. In the Type option at the bottom of the dialog box, select whether traffic will be directed to our DNS service via a CNAME record or subdomain delegation.

6. Click Add.

7. Add either an IP address or a CNAME to the failover group.

   1. Click Add.
   2. In the Value option, specify either an IP address or a CNAME's domain.
   3. In the Type option, select whether the failover group will contain IP addresses or domains (CNAME).
   4. In the Primary option, indicate whether the current configuration is for a primary server/domain.
   5. Click Add.
8. Repeat step 7 for each IP address or CNAME that should be included in the failover group. Keep in mind that the Type option is only defined once.

9. Create a health check configuration for each IP address/domain associated with your failover configuration.

   Learn more.

10. Click Submit Group to save your changes.

11. Perform one of the following:

    • CNAME Record: Create a CNAME record in a primary zone hosted on another DNS service provider that points to the system-defined domain (e.g., www.0001.edgecastdns.net) generated for the failover group. This domain can be viewed by clicking to expand the Group Information section.
    • Subdomain Delegation: From your alternate DNS service provider, delegate the subdomain (e.g., www.mydomain.com) to Route name servers. Our Route name servers can be viewed by clicking to expand the Group Information section.

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