Cool Tools Part VIII: ProxyTrace
Visibility into network traffic can be a huge help in diagnosing issues. We’ve already covered TcpTrace, which allows you to proxy traffic through it and view the traffic as it flows.
TcpTrace is great for most applications (such as monitoring traffic between ALUI portal tiers), but it can be a little limiting when you’re trying the monitor traffic between the browser and the portal. The reason for this is that you point your browser at TcpTrace and have it make the request to the portal on your behalf. This causes the browser to “see” different URLs for different content: from the browser’s perspective, portal pages are coming from http://localhost:9999/, but images and js still come from http://portal.function1.com/imageserver/. And the “host” header sent to the portal is “localhost” rather than the name of the actual server, which can result in JS errors or other unexpected server-side behavior.
A better way to monitor traffic from the browser to the portal is ProxyTrace. ProxyTrace is a virtual proxy server that routes traffic to the target site transparently, so the browser’s URL will go to http://portal.function1.com/portal/server.pt, but you’ll still be able to see the traffic because it’s routed through the proxy.
Setting up ProxyTrace is simple: you just give it a port to listen on. You don’t even need to set a destination IP and port, because that information comes from the browser. Once it’s running, you configure your browser to use this port for your proxy server (in IE, it’s Tools: Internet Options: Connections: LAN Settings):
Next time you make any HTTP requests, you’ll see all the traffic coming from the browser:
