10
•
When the IRF fabric splits, the IP addresses of the masters in the split IRF fabrics take effect.
The masters can establish a BFD session. If you execute the
display bfd session
command,
the state of the BFD session between the two devices is
Up
.
Figure 7 BFD MAD scenario with intermediate device
Figure 8 BFD MAD scenario without intermediate device
ARP MAD
ARP MAD detects multi-active collisions by using extended ARP packets that convey the IRF
domain ID and the active ID.
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.
Run the spanning tree feature between the IRF fabric and the intermediate device. In this
situation, data links can be used.
•
If an intermediate device is not used, connect each IRF member device to all other member
devices. In this situation, IRF links cannot be used for ARP MAD.
shows a typical ARP MAD scenario that uses an intermediate device.
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.
Device
Master
Subordinate
IRF fabric
IRF link
192.168.1.2/24
192.168.1.3/24
BFD MAD link
BFD MAD link
Master
Subordinate
IRF fabric
IRF link
BFD MAD link
VLAN 2
192.168.1.2/24
VLAN 2
192.168.1.3/24
