tcp client socket bind problem

[Marc Christiansen]

natambu at gmail.com wrote:
> I have a linux box with multiple ip addresses. I want to make my
> python client connect from one of the ip addresses. Here is my code,
> no matter what valid information I put in the bind it always comes
> from the default ip address on the server. Am I doing something wrong?
> 
> -------------
> #!/usr/bin/python
> 
> import socket
> 
> host = "server"
> port = 1190
> 
> sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
> 
> sock.bind(("<ipalias>",0))
> sock.connect((host, port))
> -------------

Looks good to me. Just to verify it, I added 127.1.2.3 as an address to
lo (ip addr add 127.1.2.3/8 dev lo broadcast 127.255.255.255), and...

 >>> import socket
 >>> sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
 >>> sock.bind(("127.1.2.3",0))
 >>> sock.connect(("127.0.0.1",80))

In another shell:
tolot:~> lsof -c python -a -i -nP
COMMAND  PID  USER   FD   TYPE  DEVICE SIZE NODE NAME
[...]
python  1287 tolot    3u  IPv4 3553610       TCP 127.1.2.3:38329->127.0.0.1:80 (ESTABLISHED)

Looks correct. This is using Linux 2.6.23. So, if you're doing something
wrong, it's nothing obvious to me.

Marc