Mad Mechanisms - HPE FlexFabric 5700 Series Configuration Manual

5. Shuts down all physical network ports in the Recovery-state fabrics except for the following
ports:
IRF physical interfaces.

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.
These MAD mechanisms use the following process to hand a multi-active collision:
1. Compare the member IDs of the masters in the IRF fabrics.
2. Set all fabrics to the Recovery state except the one that has the lowest numbered master.
3. Take the same action on the network ports in Recovery-state fabrics as LACP MAD.
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 active IRF fabric fails before the failure is recovered, enable the inactive IRF fabric to take
over the active IRF fabric. Then, recover the MAD failure.

MAD mechanisms

IRF provides MAD mechanisms by extending LACP, BFD, ARP, and IPv6 ND. You can configure
multiple MAD mechanisms on an IRF fabric.
•
Do not configure LACP MAD together with BFD MAD, ARP MAD, or ND MAD, because LACP
MAD handles collisions differently than these MAD mechanisms.
•
Do not configure BFD MAD together with ARP MAD or ND MAD if common Ethernet ports are
used for MAD. BFD MAD is exclusive with the spanning tree feature, but ARP MAD and ND
MAD require the spanning tree feature.
Table 1 compares the MAD mechanisms and their application scenarios.
Table 1 Comparison of MAD mechanisms
MAD
mechanism
LACP MAD
BFD MAD
Advantages
•
Detection speed is fast.
•
Does not require
MAD-dedicated physical
links or Layer 3 interfaces.
•
Detection speed is fast.
•
No intermediate device is
required.
•
Intermediate device, if
used, can come from any
vendor.
Disadvantages
Requires an intermediate
device that supports
extended LACP for MAD.
•
Requires MAD
dedicated physical
links and Layer 3
interfaces, which
cannot be used for
transmitting user traffic.
•
If no intermediate
device is used, any two
IRF members must
have a BFD MAD link
to each other.
•
If an intermediate
device is used, every
IRF member must have
7
Application scenario
Link aggregation is used
between the IRF fabric
and its upstream or
downstream device.
For information about
LACP, see Layer
2—LAN Switching
Configuration Guide.
•
No special
requirements for
network scenarios.
•
If no intermediate
device is used, this
mechanism is only
suitable for IRF
fabrics that have a
small number of
members that are
geographically
close to one
another.
For information about