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Re: number of simultaneous tcp/ip connections on 32 bit linux

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Bob Martin <bob.martin@excite.com> wrote:
>in 503286 20150727 231134 Richard Kettlewell <rjk@greenend.org.uk> wrote:
>>g918273l@gmail.com writes:
>>> I have a specific question on implementing a load balancer or a TCP/IP
>>> server program that does TCP/IP.
>>>
>>> Since port number is 16 bits, there are a max of only 65536 ports on a
>>> single Linux box at any given time.
>>> And TCP/IP needs a port number to talk to the outside world.
>>> 1) when a client establishes a connection, an ephemeral port number is chosen.
>>> 2) when a server listening on a socket accepts a connection, a port
>>> number is assigned.
>>>
>>> So in my understanding at any given time only maximum 65536 TCP/IP
>>> connections can exist on a given machine.
>>
>>A TCP connection is identified by the source address, source port,
>>destination address and destination port.  Lots more than 65536
>>possibilities.
>>
>>--
>>http://www.greenend.org.uk/rjk/
>
>True, but it doesn't answer the OP's question.

Certainly it does...  The port number only specifies the
specific server program that will respond to requests on
a given machine.  There might be many thousands of
connections to that one program, on that one port.

Consider for example that port 80 is normally assigned
to the HTTP server, and there are commonly hundreds or
thousands of browsers connected to many of the busier
web servers.

In addition to just that one port, the same machine
might also have server programs listening to dozens of
other ports at the same time.  There might be thousands
of TCP/IP connections to each of several different ports.
FTP, HTTP, HTTPS, SMTP, SSH, NTTP, POP3, and many
others.

The 16 bit size of the port number only limits the
number of services, handled by that many different
server programs.

-- 
Floyd L. Davidson                         http://www.apaflo.com/
Ukpeagvik (Barrow, Alaska)                      floyd@apaflo.com

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number of simultaneous tcp/ip connections on 32 bit linux g918273l@gmail.com - 2015-07-27 14:44 -0700
  Re: number of simultaneous tcp/ip connections on 32 bit linux Richard Kettlewell <rjk@greenend.org.uk> - 2015-07-27 23:11 +0100
    Re: number of simultaneous tcp/ip connections on 32 bit linux Bob Martin <bob.martin@excite.com> - 2015-07-28 08:04 +0100
      Re: number of simultaneous tcp/ip connections on 32 bit linux floyd@apaflo.com (Floyd L. Davidson) - 2015-07-27 23:32 -0800
        Re: number of simultaneous tcp/ip connections on 32 bit linux Richard Kettlewell <rjk@greenend.org.uk> - 2015-07-28 09:19 +0100
  Re: number of simultaneous tcp/ip connections on 32 bit linux Jorgen Grahn <grahn+nntp@snipabacken.se> - 2015-07-28 09:15 +0000
    Re: number of simultaneous tcp/ip connections on 32 bit linux Denis Corbin <news@dm3c.org> - 2015-07-28 18:29 +0200
      Re: number of simultaneous tcp/ip connections on 32 bit linux Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2015-07-28 12:51 -0400
        Re: number of simultaneous tcp/ip connections on 32 bit linux Denis Corbin <news@dm3c.org> - 2015-07-28 23:27 +0200
          Re: number of simultaneous tcp/ip connections on 32 bit linux Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2015-07-28 18:27 -0400
            Re: number of simultaneous tcp/ip connections on 32 bit linux Denis Corbin <news@dm3c.org> - 2015-07-29 09:18 +0200
  Re: number of simultaneous tcp/ip connections on 32 bit linux Jamma Tino Schwarze <jamma-usenet@tisc.de> - 2015-08-06 10:12 +0000
    Re: number of simultaneous tcp/ip connections on 32 bit linux JT <JT-reply-only@newsgroup.nl> - 2015-08-06 13:31 +0200
      Re: number of simultaneous tcp/ip connections on 32 bit linux Charlie Gibbs <cgibbs@kltpzyxm.invalid> - 2015-08-06 17:40 +0000
      Re: number of simultaneous tcp/ip connections on 32 bit linux Rick Jones <rick.jones2@hp.com> - 2015-08-06 17:04 +0000
      Re: number of simultaneous tcp/ip connections on 32 bit linux Jamma Tino Schwarze <jamma-usenet@tisc.de> - 2015-08-26 13:31 +0000
        Re: number of simultaneous tcp/ip connections on 32 bit linux Richard Kettlewell <rjk@greenend.org.uk> - 2015-08-26 18:33 +0100
          Re: number of simultaneous tcp/ip connections on 32 bit linux Jamma Tino Schwarze <jamma-usenet@tisc.de> - 2015-08-27 14:06 +0000
  Re: number of simultaneous tcp/ip connections on 32 bit linux Dumpsdrive Drive <fromdrive@gmail.com> - 2015-12-19 06:37 -0800

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