HPE FlexFabric 12900E Series Configuration Manual page 17

If common Ethernet ports are used, ARP MAD can work with or without an intermediate device.
Make sure the following requirements are met:
•
If an intermediate device is used, connect each IRF member device to the intermediate device,
as shown in
assign the ports on the ARP MAD links to the same VLAN. Run the spanning tree feature
between the IRF fabric and the intermediate device.
•
If no intermediate device is used, connect each IRF member device to all other member
devices. In this situation, IRF links cannot be used for ARP MAD.
Each IRF member compares the domain ID and the active ID in incoming extended ARP packets
with its domain ID and active ID.
•
If the domain IDs are different, the extended ARP packet is from a different IRF fabric. The
device does not continue to process the packet with the MAD mechanism.
•
If the domain IDs are the same, the device compares the active IDs.
If the active IDs are different, the IRF fabric has split.

If the active IDs are the same, the IRF fabric is integrated.

Figure 12 ARP MAD scenario
Master
ND MAD
ND MAD detects multi-active collisions by using NS packets to transmit the IRF domain ID and the
active ID.
ND MAD can work with or without an intermediate device. Make sure the following requirements are
met:
•
If an intermediate device is used, connect each IRF member device to the intermediate device,
as shown in
Figure 12. In this situation, data links can be used. On the intermediate device,
Customer
premise
network
Device
IRF
fabric
IRF link
Internet
Common traffic path
Extended ARP traffic path
Figure 13. In this situation, data links can be used. On the intermediate device,
STP domain (all devices
must run the spanning
tree feature)
Subordinate
13