Master election

Master election occurs each time the IRF fabric topology changes in the following situations:

[NOTE: ]


Master election does not occur when two split IRF fabrics merge. All member devices in the Recovery-state IRF fabric reboot to join the active IRF fabric as subordinate members. The master device of the active IRF fabric is the master device of the merged IRF fabric.

Master election selects a master in descending order:

  1. Current master, even if a new member has higher priority.

    When an IRF fabric is being formed, all members consider themselves as the master. This rule is skipped.

  2. Member with higher priority.

  3. Member with the longest system uptime.

    Two members are considered to start up at the same time if the difference between their startup times is equal to or less than 10 minutes. For these members, the next tiebreaker applies.

  4. Member with the lowest CPU MAC address.

For the setup of a new IRF fabric, the subordinate devices must reboot to complete the setup after the master election.

For an IRF merge, devices must reboot if they are in the IRF fabric that fails the master election.

[NOTE: ]


When an IRF fabric reboots, its member devices might not all finish startup at the same time because of heterogeneity in device model or in expansion interface card number or model. If the member device that first finishes startup does not detect any member device within the IRF configuration detect time, the member device becomes the master regardless of its priority. Other member devices become the subordinate devices to join the IRF fabric.