The Difference Betwen Socks4 and Socks5

Socks is a standard protocol that use to handle network traffic for TCP trough proxy server. SOCKS proxy servers are more flexible and do not seize you. While HTTP proxy servers could hide your IP only when you are browsing a web page, SOCKS proxy servers could help you keep your information private (your IP) even when you are using such programs like ICQ, Skype, MSN or even email clients like Outlook, TheBat, Thhunderbird.

there are two implementation from protocol SOCKS, here are SOCKS4 and SOCKS5.

the main difference between them are :

SOCKS4:

is a simple extension to SOCKS 4 protocol that allows a client that cannot resolve the destination host's domain name to specify it.

The client should set the first three bytes of DSTIP to NULL and the last byte to a non-zero value. (This corresponds to IP address 0.0.0.x, with x nonzero, an inadmissible destination address and thus should never occur if the client can resolve the domain name.) Following the NULL byte terminating USERID, the client must send the destination domain name and terminate it with another NULL byte. This is used for both "connect" and "bind" requests.

SOCKS5 :

provide additional security trough authentication.

socks5 is compatible with most of TCP application.

provide an base firewall for authenticate input and output packet, and

provide Network Address Translation (NAT).

support for UDP and IPv6.

Client connects and sends a greeting which includes a list of authentication methods supported.

Server responds similar to SOCKS 4.Another advantage of SOCSK5 is various authentication mechanisms

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