On Thu, May 10, 2012 at 06:03:48PM +0100, abdelkader belahcene wrote: > *Hi, > I wrote a client/server programs, the server listen on port 5000 and > of course the client connected on that port , I check the communication via > the sniffex.c program from pcap (adapting something) , I noticed that > destination port ( used by the client) is not always the same and > completely different from the source port. > Here is an output example: > > Device: lo Filter expression: ip > Packet number 1: > From: 127.0.0.1 > To: 127.0.0.1 > Protocol: TCP ---->The client send a request > Src port: 49611 ---->The port is randomly choosed by > the client ?? > Dst port: 5000 > > Packet number 2: > From: 127.0.0.1 > To: 127.0.0.1 > Protocol: TCP -----------> The answer from the server > Src port: 5000 > Dst port: 49611 > > When I stopped the client and ran it again I got another Src port from the > client > The question is : why the port opened by the client is not the same, and > takes one randomly ??
That's the way TCP/IP works. Consult any handy reference, such as TCP/IP Illustrated by W. Richard Stevens. -dsr- -- http://randomstring.org/~dsr/eula.html is hereby incorporated by reference. You can't fight for freedom by taking away rights. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/20120514033334.gb11...@randomstring.org
