Port forwarding and port triggering are both methods used to enable external access to services or applications running on a local area network (LAN). While they serve the same purpose, there are some key differences between the two.
1. Port Forwarding:
Port forwarding is a technique that allows inbound traffic to be directed to a specific device or service on a LAN. It is typically used when there is a need to expose a specific port or a range of ports on the external IP address of a network router. This enables external devices or users to access services running on devices within the LAN.
Here’s how port forwarding works:
– A port or port range is designated on the router’s configuration settings to be forwarded to a specific device on the LAN.
– When incoming traffic reaches the router on the specified port(s), the router forwards it to the designated device on the LAN.
– The device receiving the forwarded traffic then processes it and responds accordingly.
For example, let’s say you have a web server running on a device within your LAN. By setting up port forwarding on your router, you can direct incoming HTTP requests on port 80 to the IP address of the web server, allowing external users to access the website.
2. Port Triggering:
Port triggering, on the other hand, is a dynamic method of opening ports for inbound traffic. It is often used when applications or services on a LAN require different ports for incoming and outgoing communication. Unlike static port forwarding, port triggering opens a port or port range for inbound traffic only after a specific outbound traffic pattern is detected.
Here’s how port triggering works:
– A trigger port or a set of trigger ports is defined on the router’s configuration settings.
– When a user initiates outbound traffic on the trigger port(s), the router remembers this activity and opens the corresponding inbound port(s) for a specified period.
– During the specified period, any inbound traffic on the triggered port(s) is directed to the originating device on the LAN.
– After the specified period of inactivity, the triggered port(s) are closed again.
Let’s say you are playing an online game that uses a specific range of ports for communication. By configuring port triggering on your router, when you initiate outbound traffic on one of the trigger ports, the router opens the corresponding inbound ports, allowing incoming game data to reach your device. Once the game session ends, and there is no activity on the trigger ports, the inbound ports are closed again.
Key Differences between Port Forwarding and Port Triggering:
1. Static vs. Dynamic: Port forwarding is a static method where a port or range of ports is permanently opened for inbound traffic. Port triggering, on the other hand, is dynamic and opens ports temporarily based on outbound traffic patterns.
2. Inbound Traffic: Port forwarding allows for continuous inbound traffic on the specified ports, while port triggering opens ports for inbound traffic only after a specific outbound traffic pattern is detected.
3. Outbound Traffic: Port forwarding does not affect outbound traffic in any way. Port triggering requires specific outbound traffic patterns to trigger the opening of inbound ports.
4. Configuration Complexity: Port forwarding is typically simpler to configure as it involves static port mappings. Port triggering may require more advanced configuration and understanding of the application’s communication requirements.
Port forwarding and port triggering are both methods used to enable external access to services or applications on a LAN. Port forwarding is a static method that permanently opens specific ports for inbound traffic, while port triggering is a dynamic method that opens ports temporarily based on specific outbound traffic patterns. The choice between the two methods depends on the specific requirements of the application or service being accessed.