« Back to Glossary Index
Visit Us
Follow Me

In computer networking, a 5-tuple refers to a set of five values that uniquely identify a network communication flow or session. These values are used in network protocols, particularly in packet filtering and firewall rules, to match and classify network traffic. The 5-tuple consists of the following elements:

  1. Source IP address: The IP address of the sender or source device initiating the communication.
  2. Source port number: The port number on the source device that is used for the communication.
  3. Destination IP address: The IP address of the receiver or destination device for the communication.
  4. Destination port number: The port number on the destination device that is used for the communication.
  5. Protocol: The transport layer protocol being used for the communication, such as TCP (Transmission Control Protocol) or UDP (User Datagram Protocol).

The combination of these five values uniquely identifies a specific network communication flow. By examining the 5-tuple of incoming network packets, network devices like routers and firewalls can make decisions on how to handle the traffic, such as allowing or blocking it based on predefined rules.

For example, consider a TCP/IP communication between a web browser (source) and a web server (destination). The 5-tuple for this communication might be:

  • Source IP address:
  • Source port number: 54321
  • Destination IP address:
  • Destination port number: 80
  • Protocol: TCP

By analyzing the 5-tuple values of incoming packets, network devices can enforce security policies, perform network traffic shaping, or apply Quality of Service (QoS) rules based on specific protocols, ports, or source/destination IP addresses.

The 5-tuple concept is fundamental in network communication and plays a crucial role in network security, routing, and traffic management.

You may also like...