If it's a portsniffer you're looking for, I suppose you can use Asmodeus
(now known as Webtrends Security Scanner, I believe). www.asmodeus.com
From: Mike@NetDotCom <email@example.com>
To: firstname.lastname@example.org <email@example.com> ISP Tech
Date: Friday, July 31, 1998 11:42 AM
Subject: Looking for a utility
>Anyone know of a msdos or perl utility that will connect to a specific tcp
>port (like http, ot ftp) and report whether the port is responding.