What's the real different of SOCK4 and SOCK4A?

[Leo Yue]

I had found some SOCK4 resource of internet, but in the Indy, here are two
type of SOCK4 - SOCK4 & SOCK4A

After testing, I found some internet SOCK4 is SOCK4 and the others is
SOCK4A.

I want to know where is the diffrent, how can I use them uniformly?

Thanks,

Leo

[J Peter Mugaas]

I think in Socks 4, the sockified program has to do a DNS lookup for a
host name and then it has to pass the IP address to the Socks Proxy.
In Socks 4A, there's an extension for passing the hostname to the
proxy and the proxy then does the DNS lookup.

I do not think you can treat them in a Uniform way at all and Socks 5
has an authentication extension.

My advice is you give the user a choice of socks protocol proxy types
and the users can fill it in from information provided by their
network administrator.

HTH.

J. Peter Mugaas - Chairperson, Distribution Team, Indy Pit Crew
Internet Direct (Indy) Website - http://www.nevrona.com/Indy
Personal Home Page - http://www.wvnet.edu/~oma00215
If I want to do business with you, I will contact you. Otherwise, do not contact me.

[Alex Brainman]

Leo,

For diffs see:

http://archive.socks.permeo.com/protocol/socks4a.protocol

Alex