Sockets and Ports

Sockets and Ports…for dummies

Kramer RitchieMatthew loweryDevon bercegeay

PORTS

ports are 16-bit numbers between 0 and 65535 assigned to a particular

TCP/IP secession:80

Sockets

…Not that kind of socket

used as a unique address required by A tcp/ip communication process

A socket is a process’s port number plus its host machine’s IP address

TCP/IP ProtocolConnection-oriented subprotocol

Ensures reliable data delivery

Well-known Ports

Table 4-3 Commonly used TCP/IP port numbers

Range • 0-1023

Use • Operating system or Administrative

Registered PortsPort number range: 1024 to 49151less administrative privileges

Dynamic PortsPort number

range: 49152 – 65535

Also known as private ports

Open/listening port

Responds to any IP Packets destined for a specific port number

Shows that port is ready for packets

Netstat - AN

sockets

Socket SocketPair

Stored in RAM

Keeps track of status of communication

Sockets10.43.3.87 :80

Host Computer’s IP Address: Port Number:

Socket:

Why is this necessary?

The two computers communicating need to know:

where to send information

where to receive information

NEtstatThe Netstat utility allows users to see who their computers are connected to by viewing their sockets