I have a squid proxy set up. Let's pretend it is at 123.45.67.89 and, where I work, everything has to go through a CORPORATE proxy EXCEPT for port 22. At least until recently. As of this week, it appears even port 22 must go through the proxy too, by way of PuTTY's proxy settings.
When port 22 WAS open and unrestricted, I set up a squid proxy to listen on port 22, and it works with Firefox. Everything else though (PuTTY, Spotify, AWS WorkSpaces client, Fiddler2) cannot get a connection through the same IP address and port 22.
Is there a way to check whether or not port 22 is definitely blocked or not? Is it possible for it to be blocked for some applications but not Firefox? I have wireshark, but am new to it and don't know what to look for. My goal is to figure out why Firefox can use the proxy and connect through it, while nothing else can. Spotify, which used to be able to use the squid proxy just fine, also stopped working. Firefox is now the only thing that works.
It turned out the proxy was set up fine. Spotify updated and the functionality broke in their proxy connection settings. Originally, in testing, I was trying to use port 22 to ssh to the server running the proxy, since that port was already occupied by the squid proxy.
Long story short, if spotify stops working, it's probably that it updated. It seems to be a common issue.