3Com 3CRWER100-75 is a wireless cable/DSL router (widely used here, in israel). The router has a web management interface in it's port 80 (available from inside the network). When the administrator assign a virtual server to port 80 (In the management web filled under the firewall tab) and the line is not checked, the router can be remotely managed using any computer in the internet (out of the internal network). When the line is checked ? the outside message is TCP ERROR if there is no server (if there is a web server ? it will display the web site). This behavior is regardless the fact that the remote management set to off (check for the state in the management web under: Advanced- Security-Remote Administration). The router details are: 3C number 3CRWER100-75 Software version 1.2.10ww Guy Mizrahi (ZuLL) my hebrew blog: http://hacking.org.il