OpenFlow component - Port

OpenFlow defines three types of standard ports, and an OpenFlow switch must support all three:

• Physical ports
• Logical ports
• Reserved ports

Physical Ports

Physical ports correspond directly to the hardware interfaces on a switch. When a physical switch supports multiple OpenFlow logical switches, the hardware interfaces might be shared among several or all of the logical switches. In this case, the openflow physical port on a logical switch is virtual slice of the corresponding physical interface. This virtual slice is like a VLAN, or sub-interface.

A single physical interface can support multiple virtual physical ports.

Logical Ports

Logical ports do not correspond directly to hardware interfaces. This kind of interfaces you encounter on any kind of L2 or L3 switch, such as tunnel interfaces, loopback interfaces, null interfaces, MPLS LSPs, and link aggregation groups.  From the perspective of the OpenFlow process, a logical port is usually treated the same as a physical port. 

Reserved Ports  

Reserved ports are ports used for internal packet processing, for special functions such as flooding.