Irf Multi-Active Detection; Multi-Active Handling Procedure - HP 12500 SERIES Configuration Manual

Two members are considered starting up at the same time if their startup time difference is
equal to or less than 10 minutes. For these members, the next tiebreaker applies.
Member with the lowest member ID.
4.
When master election is complete, the devices that fail the master election must reboot to rejoin
the IRF fabric that wins the election. The reboot can be automatically performed or must be
manually performed, depending on the configuration. See
merge."
After a master election, all standby devices reboot with the configuration on the master, and their
original next-startup configuration files do 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.
Detection
The MAD implementation of this device detects active IRF fabrics with the same Layer 3 global
configuration by extending the LACP, BFD, or ARP protocol.
These MAD mechanisms identify each IRF fabric with a domain ID and an active ID (the member ID
of the master). If multiple active IDs are detected in a domain, MAD determines that an IRF collision
or split has occurred.
You can use at least one of these mechanisms in an IRF fabric, depending on your network
topology.
IMPORTANT:
LACP MAD handles collisions in a different way than BFD MAD and ARP MAD. To avoid conflicts,
do not enable LACP MAD together with BFD MAD or ARP MAD in an IRF fabric. However, you can
use BFD MAD and ARP MAD together.
For a comparison of these MAD mechanisms, see
Collision handling
MAD mechanisms remove multi-active collisions by setting one IRF fabric to the Active state and
other IRF fabrics to the Recovery state. Only members in the Active-state fabric can continue to
forward traffic.
LACP MAD handles a multi-active collision in the following procedure:
Compares the number of members in each fabric.
1.
Sets the fabric that has the most members to the Active state and all other fabrics to the
2.
Recovery state.
If all IRF fabrics have the same number of members, compares the member IDs of their
3.
masters.
"Enabling auto reboot for IRF fabric
"Configuring MAD."
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