Which of the following best describes the control plane of a Nexus switch?
- It is where SNMP operates.
- It is where routing calculations are made.
- It is also known as the forwarding plane.
- It is where traffic forwarding occurs.
Of the available choices, the control plane of a Nexus switch is best described as where routing calculations are made. A Nexus switch consists of three operational planes: the control plane, the management plane, and the data plane, which is also known as the forwarding plane. Routing protocols such as Enhanced Interior Gateway Routing Protocol (EIGRP), Open Shortest Path First (OSPF), and Border Gateway Protocol (BGP) all operate in the control plane of a Nexus switch. The control plane is responsible for gathering and calculating the information required to make the decisions that the data plane needs for forwarding. Routing protocols operate in the control plane because they enable the collection and transfer of routing information between neighbors. This information is used to construct routing tables that the data plane can then use for forwarding.
The data plane, not the control plane, is where traffic forwarding occurs. Cut-through switching allows a switch to begin forwarding a frame before the frame has been received in its entirety. Store-and-forward switching receives an entire frame and stores it in memory before forwarding the frame to its destination.
The management plane, not the control plane, is where Simple Network Management Protocol (SNMP) operates. The management plane is responsible for monitoring and configuration of the control plane. Therefore, network administrators typically interact directly with protocols running in the management plane.