Creating HA Groups

While creating an HA group, it is critical to ensure that all the devices in a particular HA set belong to a single IP space. In a scenario where there are four NIOS-X Servers a, b, c, and d, that are in a three HA groups with a hub and spoke design (a →b, a→c, a→ d) or a chain (a→b, b→c, c→d) the subnets for all the related peers must be in the same IP space.

For example, if you use two different IP spaces A and B, each of the IP spaces may have a subnet that contain the same IP address 10.0.0.1 which may lead to a conflict. To avoid such a scenario, it is required to have all the devices in a HA group under a single IP space.

It is highly recommended to configure NIOS-X Servers in such a way that there is no communication failure between them. This is to avoid a situation where both NIOS-X Servers are attempting to serve the same subnet at the same time due to communication failure. When the active NIOS-X Server goes down the active or passive NIOS-X Server takes over as per your configuration. However, there may be a short delay in the switchover which may result in a gap in the lease allocation. If you assign a different NIOS-X Server for the Anycast configuration on the Anycast page, you must modify the HA group to use the modified NIOS-X Server. If you change the linked protocol in the Anycast configuration on the Anycast page to DNS, you must delete the HA group. 

To create an HA group, complete the following:

1. From the Infoblox Portal, click Configure > Networking > IPAM/DHCP > HA Groups > Create HA Group.

2. On the Create HA Group page, specify the following:
   
   

   • Name: Enter a name for the HA group.

   • Description: Enter additional information about the HA group.

   • SERVICE INSTANCES:

     • HA Configuration: Select one of the following:

       • Active / Active: Both NIOS-X Servers remain active.

       • Active / Passive: One NIOS-X Server remains active and one remains passive. When the active NIOS-X Server is down, the passive NIOS-X Server takes over. 

       • Advanced Active / Passive: One host may be a part of multiple HA groups. When the active NIOS-X Server is down, the passive NIOS-X Server takes over. 

         • Active: Select a NIOS-X Server from the column selector. This is the active NIOS-X Server. 

         • Port: Displays the port number associated with the respective NIOS-X Server.

         • Active NIOS-X Server / Passive NIOS-X Server: Select a NIOS-X Server from the column selector. This is the Active NIOS-X Server if the HA Configuration is Active/Active. This is the Passive NIOS-X Server if the HA Configuration is Active/Passive. 

         • Switch Active / Passive: Click this button to switch NIOS-X Servers between Active and Passive. On clicking the button, the Active node becomes the Passive node. This feature can be used to initiate a manual failover and for troubleshooting purposes.

         • Port: Displays the port number associated with the respective NIOS-X Server.

       • Anycast: In Anycast mode, Anycast is used for configuring HA. Before creating a DHCP HA group by using Anycast, make sure Anycast is configured on the Anycast page; for more information, see Creating Anycast Configuration. DHCP with Anycast can be configured only with two nodes. On the Create HA Group page, select the Anycast configuration available: 

         • Peer Connections: Configure the peer connections for the Anycast configuration. Peer connection IPs are the addresses over which the users want two hosts in this HA group to communicate. Default values will be the two hosts' primary addresses. You can override them, but make sure that the new values represent the interfaces available on these two hosts.

         • dhcp1 → dhcp2

           • Destination IP: Specify an IPv4 address.

         • dhcp2 → dhcp1

           • Destination IP: Specify an IPv4 address.

   • Tags: For information about tags, see Managing Tags.

3. Click Save & Close to save the details or click Cancel to exit.

Status Changes in HA Peer

When an HA peer changes status (if a NIOS-X Server is down), the status is shown on the NIOS-X Servers page. Error messages related to issues with the NIOS-X Server are also displayed. For more information, see Viewing General Server Information. 

Replacing NIOS-X Server when High Availability is configured

When replacing a server that is part of a DHCP High Availability (HA) group, the system will automatically configure the peer destination address to the primary address of the new server. Once the replacement process is fully completed and the new server is visible on the HA Groups page, it is essential to verify and update the peer destination address if necessary. Neglecting this step could lead to disconnection of the new server from its peers within the DHCP HA group.

For more information on how to replace a NIOS-X Server, see Replacing Servers.