The key to HTTP tunneling is the syntax that is used to initiate tunneling from the Client station. Figure 8 illustrates the basic HTTP tunneling syntax. It also shows (lower part of the graphic) the different syntax required when the Only Tunnel Known Stations property is set to true and the station name is required instead of the host IP address.
Where:
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Proxy Server
This is the NiagaraAX-3.3 (or later) station with an IP address that is available to the client station that you are currently using. The proxy server web service port number defaults to port 80 (the standard default HTTP port) unless otherwise specified.
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Host Server
This is the station that you are trying to tunnel to. After supplying the IP address of the proxy server, complete the URL by including a slash and the word "tunnel" followed by another slash and the address of the host server. If tunneling is limited to known stations, only, then the station’s name is used in place of the host server IP address. The host server http port number defaults to port 80 (the standard default HTTP port) unless otherwise specified.
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Syntax example 1
The following graphic shows an example of a URL address for tunneling through a Proxy server (137.19.60.184) and then to the target host (137.19.61.242). If “Only Tunnel Known Stations” is enabled then the station name is used instead of the target host IP address. No port is specified for either station in this example, so HTTP port 80 is used.
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Syntax example 2
The following graphic shows an example of a URL address for tunneling through a proxy server (137.19.60.119) using the proxy server http port 82, then tunneling and connecting to the host server (137.19.60.184) using the host server http port 81.
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Syntax example 3
The following graphic shows an example of tunneling through a proxy server (137.19.60.184) that uses port 81, then through a second proxy server (137.19.61.242) and on to the target host and login view at (137.19.61.100/login). Note that port 81 is specified and used only on the proxy server station. The intermediate and target host server ports are not specified so they are assumed to be port 80.
