Python Sockets problem

Assuming you are using an ADSL router, it may have a problem routing connections to it's WAN interface from inside the LAN(I know the Netgear DG834x has this problem, which is fixed in a patch).

I don't know. If I open the command prompt and ping my real IP, it doesn't seem to have a problem.

The weird thing is, if I connect my client to '85.84.83.82':80, then the connection is accepted. It seems to me that the problem is on the server side, the client can reach my real IP but it seems like noone listens to port 2323. I tried binding the real IP to the server too instead of '' but it doesn't accept it.

Are you sure you don't have a firewall running? Port 80 is probably configured automatically, but a random port above 1023 may not be. Connecting to the loopback address bypasses any firewall completely (AFAIK). Although not being able to bind to the external IP sounds a bit odd. I haven't programmed any sockets in a while and never in Python though.

Binding to the empty string will bind the socket to localhost. Enter the complete IP address instead.

I did; it complains that 'Can't assign requested address'.

Is your router forwarding connections on 80?

Ok, my latest try has been:

server.py:

host=socket.gethostname()
port=1234
mySocket = socket.socket ( socket.AF_INET, socket.SOCK_STREAM)
mySocket.bind( (host, port) )

client.py:
host='xxx.xxx.xxx.xxx'//my real IP
port=1234
mysocket=socket.socket(socket.AF_INET,socket.SOCK_STREAM)
p=mysocket.connect( (host,port) )

It still doesn't work. When I execute 'netstat -a -n', among others I get:



If I try to connect my client with '192.168.1.2' it works(and the 'Foreign IP' column is filled), but I wanted to do it with the real IP. But my server only listens to '192.168.1.2:1234', so if I try to connect the client to my real IP the connection is refused. And I can't bind the server to my real IP because it says 'can't assign requested address'. If I execute 'ipconfig', I get '192.168.1.2' as my IP. The 'real' IP I'm referring, which lools like '32.123.78.192', I only see it when I connect to '192.168.1.1' and see my router settings, and it's not always the same. Does all of this mess has to do with the fact that my IP is dynamic(it changes every time I disconnect/connect again)? Do I need to have a static IP in order to achieve what I'm trying here?

Thanks again for the help.

Quote:

Original post by GnuVince Binding to the empty string will bind the socket to localhost. Enter the complete IP address instead.

That's incorrect. Binding to '' essentially binds to 0.0.0.0(all IP interface addresses assigned to the machine.. 127.x.x.x, and 192.168.1.2 from what I can tell).

Mikeman, you need to make sure...

1) Your router is forwarding port 80 (or whichever) to your machine on the LAN (192.168.1.2).

2) Your machine's firewall(if you have one) is allowing incoming connections to your app.

3) Your router allows connection attempts to 'jump out' of the LAN and back in through your Internet IP. Please remember some don't(as mentioned in my earlier, and very brief, post).

Ok, I'm not really an internet expert so bear with me. I have now disabled my firewall. As for port forwarding, currently there are no 'rules' applied. So I try to create one and this is exactly what I get:

WAN Connection: quick_start
LAN IP: 192.168.1.2

Rule name:example
Protocol:TCP
Port Start:????
Port End:????
Port Map:????

Assumming I want all this to work for port 2323, what values do I need to enter in "Port Start","Port End","Port Map"?

Also,there is a 'custom rule' option that has all the above fields and some additional ones(Application,Source IP,Destination IP,Source NetMask).

What type of router are you using? Most home routers just have the port start and port end boxes. Put 2323 for both the start and end to make it only forward that port. I don't know what Port Map does or if it is required. It probably allows you to forward connections from one port to another port, so just try leaving it blank for now.

I did that, same deal.

Ah, forget it, it's not worth it and I'm tired :) I may ask one of my proffesors if he can help. Thanks anyway, guys.

Quote:

Original post by mikeman If I try to connect my client with '192.168.1.2' it works(and the 'Foreign IP' column is filled), but I wanted to do it with the real IP. But my server only listens to '192.168.1.2:1234', so if I try to connect the client to my real IP the connection is refused. And I can't bind the server to my real IP because it says 'can't assign requested address'.

The fundamental problem here is that what you call your "real IP" address is not your IP address. That's why it doesn't show under netstat. It belongs to your router. It really has nothing to do with your computer. Requests to that address are just forwarded on your behalf if you've configured the router to do so. You are on a totally different network to the address you want to use; it just happens that your modem/router passes data across the boundary.