There are many reasons to keep a web application behind a firewall. Protecting unsecured data and credentials, hiding new features, and general security are all common concerns of software teams. However, just because a web application hasn’t been made public, it should not excuse or delay testing across environments.
Internal Website Behind a Firewall
This the default option and routes traffic from the remote machine to the client machine, which allows you to test to websites hidden behind a firewall. The extension/module connects to the tunnel server, which is used as a proxy by the remote machine. Then the extension/module sends and receives data through an SSL-encrypted WSS connection with the tunnel server.
Local HTML file mode allows specified local files on the client machine to be hosted and tested with the CrossBrowserTesting web app. A simple static HTTP server is spun up on the client machine on the first free port between 8080 and 8089 (or a port specified by the user) and provides the remote machine with read-only access. The HTTP server is terminated at the same time as the local tunnel.
External Proxy Service
Proxy server mode allows web traffic from the remote machine, which is routed through the tunnel to the client machine, to be further routed through a specified proxy server. This is useful for corporate environments that require proxies for HTTP/HTTPS traffic.