Python socket bind to any IP?

Question

I have a small one sided message sender that works while I specify the IP to connect to in code, however, I am having trouble allowing the socket to accept connections from any IP. Here is the line that is the problem.

mySocket = socket.socket ( socket.AF_INET, socket.SOCK_STREAM )
mySocket.bind ( ( '', 2727 ) )

The '' is for localhost, and it works if I manually enter IP, eg '192.168.1.106', however, how can I leave it open to all? Or am I using the wrong connection type for this?

score 49 · Accepted Answer · edited Apr 13 '17 at 12:13

49

If you want to bind to all available IPv4 addresses, specify 0.0.0.0 as your IP address. If you're behind a router and wish to have your socket internet-accessible, rather than just available on your LAN, you'll need to set up a port forwarding rule so that users outside your LAN can access the service.

See the following ServerFault question for more info on 0.0.0.0: https://serverfault.com/questions/78048/whats-the-difference-between-ip-address-0-0-0-0-and-127-0-0-1

edited Apr 13 '17 at 12:13

Community

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answered Nov 07 '11 at 07:03

Polynomial

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Is it possible to bind to completely custom ips like 152.64.87.9? – CMCDragonkai Jun 12 '14 at 11:31
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@CMCDragonkai Only if your system has an interface with that address. – Polynomial Jun 12 '14 at 15:55
So I would need to create these interfaces prior to binding to them. And creating virtual interfaces would be loopbacks right? – CMCDragonkai Jun 13 '14 at 04:34
Would that be IPv4 only? What about binding on all available IPv6 addresses? – Craig McQueen Mar 08 '18 at 01:15

score 16 · Answer 2 · answered Nov 07 '11 at 08:21

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Binding to '' has the same effect as to '0.0.0.0' makes the transition to IPv6 easier.

Depending on the OS, opening a socket.AF_INET6 socket listens to IPv4 and IPv6.

answered Nov 07 '11 at 08:21

glglgl

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Python bug report to make the docs more explicit about this: https://bugs.python.org/issue33921 – phoenix Jun 21 '18 at 11:17
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According to the [docs](https://docs.python.org/3/library/socket.html#socket-families), `''` is **not** compatible with IPv6: *This behavior is not compatible with IPv6, therefore, you may want to avoid these if you intend to support IPv6 with your Python programs.* – phoenix Jun 23 '18 at 14:44

score 6 · Answer 3 · answered Nov 07 '11 at 07:03

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Binding to 0.0.0.0 will allow it to accept connections from any IPv4 address that can route to it.

answered Nov 07 '11 at 07:03

Ignacio Vazquez-Abrams

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Python socket bind to any IP?

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