I'm creating a simple python program at a client computer (Linux Ubuntu) :
#import sys
from socket import *

def init():
s = socket(AF_INET, SOCK_STREAM)
hostname = '192.168.100.100'
port = 1973
s.connect((hostname, port))
code = chr(203) + chr(214) + chr(201) + chr(198) + chr(001)
stationid = '30';
s.send(code + 'TEST LINUX');

this will connect to a Server program I'm create on WinXP Computer
But got :

>>> import client
>>> client.init()
Traceback (most recent call last):
File "<stdin>", line 1, in ?
File "client.py", line 8, in init
s.connect((hostname, port))
File "<string>", line 1, in connect

socket.error: (111, 'Connection refused')
>>>

Trying to ping the server 192.168.100.100, it replies nicely
Already input port 1973 from all computers on both firewall inbound and outbound.
Even trying to disable or turn off both computer firewall
But still it the same 111, connection refuse
Trying telnet 192.168.100.100 1973 the same refused

What is wrong ?

Thank You

It's a little hard to tell without seeing what your server is doing. Are you sure it was listening on the correct port?

I'm sure, because I'm also creating a client program for Windows XP it is work great if both is Windows OS, but when I'm doing it in Python Linux got problem like that

Both linux - winXP computer can see each other in network, and they can send and receive file on each file explorer, so the network connection is ok. Both can ping each other nicely too, just my python program always got conection refused when sending to a server program (which I create), though it is ok when another client connect and do several communication with the server when the client is WinXP.

is there anything I should know more with windows - linux socket programming ?
does my program already correct ? or something should be tweaked on the windows or linux side to allow the connection passing?

Thank You

So you are saying that you run the same (client) python program from WinXP, and you can connect to the server? That is a little odd. Everything you are doing sounds correct. If your Linux box is not blocking outbound port 1973 (check with "iptables -n -L") and your server is not blocking inbound port 1973 and the server is running, then it should work fine. Do you have any other servers running on WinXP like an FTP server or a web server? Can you get a socket to connect to one of those ports?

iptables -n -L :
Chain OUTBOUND (1 references)
target prot opt source destination
ACCEPT icmp -- 0.0.0.0/0 0.0.0.0/0
ACCEPT all -- 0.0.0.0/0 192.168.100.100

.......

ACCEPT tcp -- 0.0.0.0/0 0.0.0.0/0 tcp dpt:1973
ACCEPT udp -- 0.0.0.0/0 0.0.0.0/0 udp dpt:1973
LOG all -- 0.0.0.0/0 0.0.0.0/0 LOG flags 0 level 6 prefix `Outbound '
REJECT all -- 0.0.0.0/0 0.0.0.0/0 reject-with icmp-port-unreachable

The working client (which in WinXP) crated using Delphi and so the Server program. I'm using python only on Linux Client. But the code exactly the same as in python, I'm just translate it into python.
I do place outbound policy to allow port 1973 to all computers
In windows side the firewall is norton antivirus worm protection and I do open inbound port 1973 there
Even I've tried several times on both deactivate the firewall altogether, but to no avail...

Is there anything I'm miss here ?
Or socket coding from Delphi and Python need something extra things to do ?
Isn't that socket is standard accros platform ?

Thank You

Here are a couple ideas:

It looks like your Linux box is running some sort of firewall (maybe firestarter?). Try disabling it and then:
to flush the chains in the filter table. That should pretty much eliminate the Linux firewall as a problem.

Next, you might want to install ethereal or windump on your XP machine so you can watch the packets come over. You can compare the exchanges between a working and a non-working client. Figure out what the difference is.

The sockets model is supposed to be the same across platforms in theory, but I am pretty sure that there are some implementation differences.

I think needed a clearence here, is socket(AF_INET, SOCK_STREAM) create a TCP or UDP socket ?
Because I'm using UDP protocol on the WinXP side.
is DATAGRAM the correct one ?
How to correct it in python, please help

Thank You

wow Succeess SOCK_DGRM

Anyway thank you Carl, because u point out of using ethreal I'm realize that I didn't use the same protocol at the first place.

THANK YOU ALOT CARL, you are very GENIUS