Port address, logical and physical address
Port, Physical and Logical Address
Ø Port address is a feature of a network device that translates TCP or UDP communications made between a host and port on an outside network
Ø It allows a single IP address to be used for many internal hosts.
Ø Port address can automatically modify the IP packets' destination or source host IP and port fields belonging to its internal hosts.
Ø Frames need to be transmitted to different systems on a network.
Ø Data link layer adds a HEADER to frame.
Ø Header defines the physical address of sender (Source address) and receiver address (Destination address).
Ø Frame is intended for a device outside the network.
Ø If a packet is going from one network to another, need another addressing system to help distinguish source and destination systems
Ø Network layer adds Header to the data coming from upper layers that among other things include LOGICAL ADDRESS of the sender and receiver.