Why doesn't IE/Chrome on Windows support SOCKS5 proxies on port 27977?

Question

I am working with a client who uses proxies on their Windows machines. They recently have come to me to solve the issue of why Interenet Explorer and Chrome refuse to use SOCKS5 proxies on port 27977. I believe it has something to do with the fact that all the proxies on 27977 are implemented in pure SOCKS5. I can get Firefox to work just fine with these proxies in Windows, as well as Chrome under Ubuntu. Sidenote: my Nexus One will work with them too on Firefox for Android. I am wondering if their is a patch, or if IE9 would have better support etc. Thanks for any help guys.

Answer 1

1 answer here

http://forum.my-proxy.com/socks-proxy-list-service/why-ie-can-not-use-the-27977-port-proxies-t13327.0.html

The 27977 port socks proxies are pure socks5 proxy which only support socks5 protocol. IE (and Chrome) regards all the socks proxy as socks4 by default so IE can not use them.

Most socks5 proxies support both socks5 and socks4 protocol. They can be used as either socks5 or socks4 proxy. So IE can use other socks5 proxies but 27977 socks.

Firefox can set the version of the socks proxy so Firefox can use 27977 port proxies as well as curl.