Before you can create an xHA pair in Address Manager, you must meet the following requirements:
- You have at least two connected and managed DNS/DHCP Servers in the configuration.
- The DNS/DHCP Servers are either two physical appliances or two virtual machines. Mixed xHA pairs (one appliance and one virtual machine) are NOT supported.
- Both DNS/DHCP Servers are at the same software version.
- Both DNS/DHCP Servers are the same profile, such as two DNS/DHCP Server 60 or two DNS/DHCP Server 100 profiles.
- To create an xHA pair with the active node on which the dedicated management interface is enabled, the dedicated management interface on the passive node must be enabled.
- The active and passive nodes are on the same network.
- The servers for the xHA pair are not associated with a deployment schedule.
- The server intended for the passive role is not associated with a deployment role.
- To avoid a split-brain scenario (where both servers are active or passive at the same time), you must configure an xHA backbone connection. Refer to Using the xHA backbone connection in the Address Manager Administration Guide for details.
- If you are currently using the xHA/eth1 ports for another purpose, you can reset and then reconfigure them for xHA communication, but you cannot use the eth1 ports for xHA communication and for their previous purpose.
- If you are upgrading from a previous version of DNS/DHCP Server, you must delete each eth1 port to reset it. This is because previous versions did not support eth1, and it's not reset automatically.