7
3.
Compare the member IDs of the masters if all IRF fabrics have the same number of members.
4.
Set all fabrics to the Recovery state except the one that has the lowest numbered master.
5.
Shut 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, ARP MAD and ND MAD do not compare the number of members in fabrics. These MAD
mechanisms use the following process to handle 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 and BFD
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 a
minimum of one MAD mechanism on an IRF fabric for prompt IRF split detection.
•
Do not configure LACP MAD together with ARP MAD or ND MAD, because they handle
collisions differently.
•
Do not configure BFD MAD together with ARP MAD or ND MAD. BFD MAD is mutually
exclusive with the spanning tree feature, but ARP MAD and ND MAD require the spanning tree
feature. At the same time, BFD MAD handles collisions differently than ARP MAD and ND MAD.
compares the MAD mechanisms and their application scenarios.
Table 1 Comparison of MAD mechanisms
MAD
mechanism
Advantages Disadvantages
Application
scenario
•
Detection speed is fast.
•
Does not require
MAD-dedicated physical
links or Layer 3 interfaces.
Requires an intermediate
device that supports
extended LACP for MAD.
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
.
•
Detection speed is fast.
•
No intermediate device is
required.
•
Intermediate device, if
used, can come from any
vendor.
•
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
•
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
