Broadcast domain overview (ONTAP 9.8 and later)
Broadcast domains are intended to group network ports that belong to the same layer 2 network. The ports in the group can then be used by a storage virtual machine (SVM) for data or management traffic.
A broadcast domain resides in an IPspace. During cluster initialization, the system creates two default broadcast domains:
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The "Default" broadcast domain contains ports that are in the "Default" IPspace.
These ports are used primarily to serve data. Cluster management and node management ports are also in this broadcast domain.
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The "Cluster" broadcast domain contains ports that are in the "Cluster" IPspace.
These ports are used for cluster communication and include all cluster ports from all nodes in the cluster.
The system creates additional broadcast domains in the Default IPspace when necessary. The "Default" broadcast domain contains the home-port of the management LIF, plus any other ports that have layer 2 reachability to that port. Additional broadcast domains are named "Default-1", "Default-2", and so forth.
Example of using broadcast domains
A broadcast domain is a set of network ports in the same IPspace that also has layer 2 reachability to one another, typically including ports from many nodes in the cluster.
The illustration shows the ports assigned to three broadcast domains in a four-node cluster:
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The "Cluster" broadcast domain is created automatically during cluster initialization, and it contains ports a and b from each node in the cluster.
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The "Default" broadcast domain is also created automatically during cluster initialization, and it contains ports c and d from each node in the cluster.
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The system automatically creates any additional broadcast domains during cluster initialization based on layer 2 network reachability. These additional broadcast domains are named Default-1, Default-2, and so forth.
A failover group of the same name and with the same network ports as each of the broadcast domains is created automatically. This failover group is automatically managed by the system, meaning that as ports are added or removed from the broadcast domain, they are automatically added or removed from this failover group.