1. Network Device Planes of Operation:
   1. Data (Forwarding) Plane
      1. Forwarding data to the next-hop
         1. ACLs
         2. TCAM
         3. CAM
         4. IP Routing Table
   2. Control Plane
      1. How forwarding decisions are made on the device:
         1. Spanning-Tree Protocol
         2. OSPF
         3. SDM Templates
   3. Management Plane
      1. How configuration changes are managed on the device:
         1. SSH
         2. OpenFlow
         3. SNMP
2. Networking Systems Models
   1. Networking systems may be designed such that the three plane functions of the devices that make them up operate in one of two ways:
      1. Distributed Systems
         1. A device is responsible for all three planes.
      2. Centralized Systems
         1. The control plane, and potentially the management plane, are operated from a centralized location for many devices in a network.
3. SDN Information Management
   1. Software-Defined Networking (SDN) network models and technologies use a centralized system.
   2. Using a centralized model, information is managed differently from traditional networking models in two ways:
      1. Southbound API
         1. Information is communicated between the SDN controller and networking devices, using:
            1. OpenFlow
            2. SNMPv3
            3. Cisco OpFlex
            4. NETCONF over SSHv2
      2. Northbound API
         1. Information is communicated between the SDN controller and services and applications running over the network. These services and applications are used to automate tasks and allow network programmability.
            1. Puppet
            2. Salt
            3. Chef
            4. Ansible
4. SDN Security Benefits and Concerns
   1. Benefits:
      1. SDN allows fine-grained network configuration.
      2. Strong security practices that are typically difficult or impractical to deploy can be accomplished through SDN.
      3. SDN allows faster responses to network security issues.
   2. Concerns:
      1. SDN increases network complexity.
      2. Even more than in traditional distributed systems, SDN requires the use of strong access controls. This is required to protect its centralized controller against attacks.