Member Priority; Master Election; Irf Multi-Active Detection; Multi-Active Handling Procedure - HP 7500 series Configuration Manual

Figure 6 IRF merge
IRF 1
Device A

Member priority

Member priority determines the possibility of a member device to be elected the master. A member with
higher priority is more likely to be elected the master.
The default member priority is 1. You can change the member priority of a member device to affect the
master election result.

Master election

Master election is held each time the IRF fabric topology changes, for example, when the IRF fabric is
established, a new member device is plugged in, the master device fails or is removed, the IRF fabric
splits, or IRF fabrics merge.
Master election uses the following rules in descending order:
Current master, even if a new member has higher priority.
1.
When an IRF fabric is being formed, all member switches consider themselves as the master, and
this rule is skipped.
Member with higher priority.
2.
Member with the longest system uptime.
3.
Member with the lowest member ID.
4.
The IRF fabric is formed on election of the master.
During an IRF merge, the switches of the IRF fabric that fails the master election must reboot to re-join the
IRF fabric that wins the election. The reboot can be automatically performed or manually performed,
depending on the configuration. See
After a master election, all subordinate switches reboot with the configuration on the master. Their
original configuration, even if it has been saved, does not take effect.

IRF multi-active detection

An IRF link failure causes an IRF fabric to split in two IRF fabrics operating with the same Layer 3
configurations, including the same IP address. To avoid IP address collision and network problems, IRF
uses multi-active detection (MAD) mechanisms to detect the presence of multiple identical IRF fabrics,
handle collisions, and recover from faults.

Multi-active handling procedure

The multi-active handling procedure includes detection, collision handling and failure recovery.
IRF 2
+
=
Device B
XGE1/3/0/1
Device A
"Enabling auto reboot for IRF fabric
7
IRF
XGE2/3/0/1
IRF link
Device B
merge."