How does Ngrok bypass firewalls to expose local services to the internet?

Ngrok's Firewall-Penetrating Mechanism

Ngrok empowers users to expose local services to the internet despite potential firewall barriers. By initiating a tunnel from the client to the server, ngrok bypasses firewall restrictions.

Client-Initiated Tunnel

Unlike traditional firewall configurations that block incoming traffic, ngrok operates by having the client initiate a secure channel with the server. This single, persistent TCP connection establishes a bidirectional communication channel.

Stream Multiplexing

Within the client-server connection, ngrok utilizes stream multiplexing. This technique creates multiple logical sockets within a single physical connection, eliminating the need for polling requests. Instead, the client and server maintain constant communication.

Heartbeat Mechanism

To ensure connection integrity, ngrok employs a heartbeat mechanism. This regular check confirms the connection's availability and functionality. In the event of a disrupted connection, ngrok automatically re-establishes it.

For further details, refer to the Developer Guide on github.com.

The above is the detailed content of How does Ngrok bypass firewalls to expose local services to the internet?. For more information, please follow other related articles on the PHP Chinese website!