Hi! Yesterday, I somehow decided to dowload a port scanner, so, I downloaded it, and ran it against some servers and my own personal system. However, this is what I found out. This scanner is simple an fast, and it supports TCP and UDP scan. The only thing that surpised me is that it seems that according to the scanner, all of my TCP ports are either closed or invisible, but however most of my UDP ports (almost all) are open.

So... I decided to run a UDP port scan against two other servers. Netscape.com, and Thawte.com. The result? Most of the UDP ports were reported in the port scanner windows ( assume that then it means those ports are open as this is what happened when I did TCP scan, all open ports were reported). Even on netscape.com or thawte.com, most UDP ports are open. What does this mean? Does this mean that Firewalls today only protects you against attacks launched from the TCP protocol and not UDP?

Thankx