Lacp Mad - HP 5900 Series Configuration Manual

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, ARP MAD, and ND MAD. To avoid
conflicts, do not enable LACP MAD together with any of those mechanisms in an IRF fabric. However, you
can use BFD MAD, ARP MAD, and ND 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 Recovery
2.
state.
If all IRF fabrics have the same number of members, compares the member IDs of their masters.
3.
Sets the IRF fabric that has the lowest numbered master to the Active state and all other fabrics to
4.
the Recovery (disabled) state.
Shuts down all physical network ports in the Recovery-state fabrics but their physical IRF ports and
5.
any ports you have specified with the mad exclude interface command.
In contrast, BFD MAD, ARP MAD, and ND MAD do not compare the number of members in fabrics. They
directly set the IRF fabric that has the lowest numbered master to the Active state, set all other fabrics to
the Recovery state, and take the same action on the network ports in Recovery-state fabrics as LACP MAD
does.
Failure recovery
To merge two split IRF fabrics, first repair the failed IRF link and remove the IRF link failure.
If the IRF fabric in Recovery state fails before the failure is recovered, repair the failed IRF fabric and the
failed IRF link.
If the IRF fabric in Active state fails before the failure is recovered, first enable the IRF fabric in Recovery
state to take over the active IRF fabric and protect services from being affected. After that, recover the
MAD failure.

LACP MAD

LACP MAD requires that every IRF member have a link with an intermediate device, and all these links
form a dynamic link aggregation group, as shown in
that supports extended LACP for MAD.
The IRF member devices send extended LACPDUs with TLVs that convey the domain ID and the active ID
of the IRF fabric. The intermediate device transparently forwards the extended LACPDUs received from
one member device to all the other member switches:
"Configuring MAD."
Figure 5. The intermediate device must be a device
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