I built a test app that consists of both an HTML5/WebSocket client and an HTTP/WS server. The servers are written in C#, with my own simple HTTP server and a WS server based on concepts from . The HTTP server listens on 0.0.0.0:5959, and the WS server is listening on 0.0.0.0:5960 (accepting connections from any client but on different ports).
In my index.html file, there's some JavaScript code that establishes a WebSocket connection to
'ws://'+document.location.hostname+':5960/'The HTTP server works fine from any client, whether it's a browser on my machine accessing 127.0.0.1:5959 or localhost:5959, or even when a remote machine pings my server's internal IP at 10.122.0.159:5959. Everything functions as expected in the realm of HTTP.
However, the WebSocket only seems to function on 127.0.0.1 and localhost; remote machines can retrieve HTML from 10.122.0.159:5959, yet the WebSocket fails to connect to 10.122.0.159:5960. Even pointing my local browser to its own 10-net address (10.122.0.159:5959) produces the same outcome - the HTML loads but the WebSocket connection does not occur.
Do you have any insights into why this might be occurring? Does CORS mandate that the WS must use the same port as the originating HTTP request? And is there a special exemption for 127.0.0.1?
Thank you,
-Dave
Update
It appears that a proxy server is causing the issue with the ws:// requests. Our company employs a proxy server for content filtering and other functions, which our browsers are configured to use.
Chrome follows IE's proxy settings, and by default, IE does not utilize a proxy server for localhost. When I enable the proxy server for local connections, my ws:// requests to localhost are blocked. Conversely, disabling the "use proxy server" setting allows my server to receive the WS request. The same applies for remote machines - turning off the proxy enables my server to receive the ws:// request.
Therefore, it seems to be related to the proxy configuration rather than CORS or socket issues. Now, I will delve into the proxy settings with our IT team.