Re: TCP/IP Ports

From: Neil Horman (nhorman_at_rNeOdShPaMt.com)
Date: 12/08/03 

Date: Mon, 08 Dec 2003 08:22:33 -0500

Awie wrote:
> All,
>
> I am sorry to ask a very basic question. But I am rather confuse about
> TCP/IP Port and need to make sure. Hope you would explain me.
>
> Let say I want to access a WEB server
>
> 1. Will my computer use un-privilege port (above 1024) to destination
> server or use port 80?
You will send a connection request to port 80 on the remote (server)
machine)
> 2. What port will be received by my computer? Is it port 80 or
> un-privilege?
The server will establish a new socket with you in response to the
connect request in (1) on a port above 1024 (remembering that the web
server application can only request unprivlidged ports as well)

> 3. How is about SMTP port? Is it like HTTP or using port 25 for both
> direction?
All TCP connections from user space applications are the same. You send
a connection request to a well-known port (sometimes a privlidged one if
the app has been configured that way) and the actuall connection is
established on an unprivlidged port.

>
> Many thanks for your kind help.
>
> Best Regards,
>
> Awie 

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