Applicable Versions
NetSim Academic
NetSim StandardNetSim Pro


Applicable Releases
v10.2
v11
v12
v13


Layer 3 devices such as Routers and L3 Switches are said to be the boundary of broadcast domains and broadcast packets aren't sent across different interfaces of these devices. 

In a LAN, Nodes connected to the same L2 Switch belong to the same broadcast domain.

In the above example Wired Node B, Wired Node D, and Wired Node C belong to the same broadcast domain. 

In the case of Inter-connected LAN segments, nodes connected to interconnected L2 switches are members of the same broadcast domain. 

In the above example Wired Node B, Wired Node D, Wired Node C, Wired Node F, Wired Node G and Wired Node H belong to the same broadcast domain. 

In the above example, Router I acts as a boundary between the two broadcast domains formed by L2 Switch A and L2 Switch E.  Wired Node B, Wired Node D, and Wired Node C belong to a broadcast domain formed by L2 Switch A whereas, Wired Node F, Wired Node G, and Wired Node H belong to a different broadcast domain formed by L2 Switch E. 


If broadcast traffic is configured, packets will be received by those devices which are within the broadcast domain. This is the reason why packets of broadcast packets don't reach devices belonging to different broadcast domains.