Thank you for the great explanation. I understand. "R. Scott Perry" <[EMAIL PROTECTED]> wrote:
> >>02:03 00:01 SMTPD(197A0138) [134.241.135.2] connect 128.205.7.57 port 56561 > >If you check the rest of your logs, you'll see that is completely >normal. Those are simply port 25 connections. > >Each TCP/IP connection has 4 pieces of information that uniquely identify >it: The local IP address, the remote IP address, the local port, and the >remote port. In this case, the local IP is 134.241.135.2, the remote IP is >128.205.7.57, the local port is port 25, and the remote port is port >56561. That's all; nothing unusual about it. > >If you're not familiar with TCP/IP connections, you might assume that both >sides would use port 25. However, this is not the case. Since the TCP/IP >connections require those 4 pieces of information, if the remote port had >to use port 25, it would only be able to have 1 SMTP connection at a >time. By using different ports on the remote end, the can have multiple >simultaneous connections. > >In real life usage, you'll always see one commonly used port on the server >side (such as port 25 for SMTP or port 80 for web), and a seemingly random >port on the client side (typically starting at 1024 and going up by 1 for >each new connection, but that depends on the TCP/IP stack). > >If you type "netstat -n" from a command prompt (on the mail server, or even >your workstation), you'll see that for each connection there is a >recognizable port on one side of the connection (IE 80 for web), and an >unrecognizable one on the other side. > > -Scott >--- >Declude: Anti-virus, Anti-spam and Anti-hijacking solutions for >IMail. http://www.declude.com > >--- >[This E-mail was scanned for viruses by Declude Virus (http://www.declude.com)] > > >Please visit http://www.ipswitch.com/support/mailing-lists.html >to be removed from this list. > >An Archive of this list is available at: >http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ > -- __________________________________________________________________ Your favorite stores, helpful shopping tools and great gift ideas. Experience the convenience of buying online with Shop@Netscape! http://shopnow.netscape.com/ Get your own FREE, personal Netscape Mail account today at http://webmail.netscape.com/ Please visit http://www.ipswitch.com/support/mailing-lists.html to be removed from this list. An Archive of this list is available at: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/
