Wireshark-users: Re: [Wireshark-users] How source and destination is identified in Wireshark?

From: Andrew Hood <ajhood@xxxxxxxxx>
Date: Sat, 29 Jan 2011 12:38:01 +1100
ronnie sahlberg wrote:
> Yes.
> 
> My rationale was this :
> 
> In the conversation list the socket pairs are deliberately set up with the
> "highest" port to the left and the "lowest" port to the right.
> 
> Almost always, clients will use ephemeral ports in the >=32768 range
> and server applications will listen on system ports <2048

This tends to fail on Windoze, where ephemeral ports can start at 1024
and many well known services are higher than that.

It takes an explicit registry change and reboot to alter this behaviour.
You have to reserve sockets below 32768

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\ReservedPorts
= '1-32767'

and make high ports available

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters\MaxUserPort
= 49151 (there are reasons for not using 65535).

-- 
There's no point in being grown up if you can't be childish sometimes.
                -- Dr. Who