For those familiar with using SOCKS proxies, you might want to know what makes SOCKS4 different from SOCKS5. In a nutshell, version 5 of the protocol is more advanced. Here is a list of features that only apply to ver. 5:

• Authentication
• Support for UDP Proxy
• DNS requests Can be sent through the proxy

Which version you use depends on the configuration of the server you’re connecting to. It will either support 4, 5 or both. SOCKS4a is an extension that fixes a common name resolution problem. Check with your network administrator, Internet service provider or proxy service provider for the proper settings. If you are using VectroTunnel, see the member’s area for help. Many popular applications support SOCKS proxies, such as Firefox, Safari, Chrome, Opera, Thunderbird and others.