Adding failover relationships for ISC DHCP - User Guide - BlueCat Horizon

BlueCat Horizon User Guide
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en-US
Product name
BlueCat Horizon

While ISC DHCP servers handle operations at the DHCP pool level, DDI orchestrator manages failover relationships at both the scope and server levels. Scopes group IP addresses logically and help to manage failover efficiently. DHCP configurations can be customized per scope to suit the specific requirements of different network segments.

Note: When the first scope is added to the failover relationship, the failover peer statement is created on the server. All address pools within the scope will be updated to refer to this failover peer.

Adding failover relationships in DDI orchestrator

To add a failover relationship in DDI orchestrator:

  1. On the Admin page, select the Service management tab.
  2. In the left sidebar, under DHCP services, select ISC DHCP.
  3. Select the ISC DHCP server housing the scope for which you want to establish failover configuration, and then use either the Action menu or the ellipses in the row to select Manage failover.
  4. In the dialog, select + Add relationship.
  5. In the Initial setup step, enter the following information:
    The Initial setup step of the Add relationship dialog for an ISC DHCP server.
    • Failover name: Specify the name of the failover peer.
    • Partner server: Select the partner server for the failover configuration.
    • Port: Specify the port number on which the server should listen for connections from its failover peer.
    • Partner port: Specify the port partner on which the failover partner listens for connections.

    Then select Next.

  6. In the Options step, enter the following information:
    • Maximum client lead time: Enter the number of seconds for which a lease can be renewed by either server without contacting the other. Only specified on the primary failover peer.
    • Max response delay: Enter the number of seconds that may pass without the server receiving a message from its failover peer before it assumes that the connection has failed.
    • Load balance max seconds: Enter the cutoff, in seconds, after which load balancing is disabled. The ISC documentation recommends a value of 3 or 5.
    • Max unacked updates: Enter the number of messages the server can send before receiving an acknowledgment from its failover peer. According to ISC documentation, 10 seems to be a good value.
  7. After confirming the details in the Summary step, select Add.