Re: sockets: bind to external interface

From	Thomas Rachel <nutznetz-0c1b6768-bfa9-48d5-a470-7603bd3aa915@spamschutz.glglgl.de>
Newsgroups	comp.lang.python
Subject	Re: sockets: bind to external interface
Date	2011-04-25 23:18 +0200
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Message-ID	<ip4oed$gcc$2@r03.glglgl.eu> (permalink)
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Am 25.04.2011 22:30, schrieb Chris Angelico:

> If you don't care what port you use, you don't need to bind at all.
> That may be why it's not mentioned - the classic TCP socket server
> involves bind/listen/accept, and the classic TCP client has just
> connect; bind/connect is a lot less common.

That is right, but I cannot see where he mentions the "direction" of the 
socket. My fist thought was that he tries to have a server socket...

(BTW: bind can be omitted on server sockets as well; listen() seems to 
includes a bind(('', 0)) if not called explicitly before. In this case, 
the port is assigned randomly. Can be useful in some cases, where the 
port number is not fixed...)


> Incidentally, interfaces don't have to correspond 1:1 to network
> cards. At work, we have a system of four IP addresses for each server,
> even though it has only one NIC - it's used for traffic management and
> routing. Binding to a specific address is sometimes important there.

If you use IPv6 and activate the privacy extensions (in order to 
periodically create a new IP address), a NIC will have even more 
addresses - the ones which aren't used any longer will be kept for a 
certain time on order not to kill any existing connections.


Thomas

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Thread

sockets: bind to external interface Hans Georg Schaathun <hg@schaathun.net> - 2011-04-25 20:37 +0100
  Re: sockets: bind to external interface Chris Angelico <rosuav@gmail.com> - 2011-04-26 05:49 +1000
    Re: sockets: bind to external interface Jean-Paul Calderone <calderone.jeanpaul@gmail.com> - 2011-04-25 13:13 -0700
    Re: sockets: bind to external interface Hans Georg Schaathun <hg@schaathun.net> - 2011-04-25 21:14 +0100
      Re: sockets: bind to external interface Hans Georg Schaathun <hg@schaathun.net> - 2011-04-25 21:24 +0100
        Re: sockets: bind to external interface Chris Angelico <rosuav@gmail.com> - 2011-04-26 07:21 +1000
      Re: sockets: bind to external interface Chris Angelico <rosuav@gmail.com> - 2011-04-26 06:30 +1000
        Re: sockets: bind to external interface Thomas Rachel <nutznetz-0c1b6768-bfa9-48d5-a470-7603bd3aa915@spamschutz.glglgl.de> - 2011-04-25 23:18 +0200
          Re: sockets: bind to external interface Chris Angelico <rosuav@gmail.com> - 2011-04-26 07:50 +1000
          Re: sockets: bind to external interface Hans Georg Schaathun <hg@schaathun.net> - 2011-04-26 06:20 +0100
      Re: sockets: bind to external interface Thomas Rachel <nutznetz-0c1b6768-bfa9-48d5-a470-7603bd3aa915@spamschutz.glglgl.de> - 2011-04-25 23:14 +0200
  Re: sockets: bind to external interface Jean-Michel Pichavant <jeanmichel@sequans.com> - 2011-04-26 11:24 +0200

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