+ 1 Votes Cisco 2821 Open ports toothache90 6 years ago Hi, You can use the GUI to check what ports are default open. Simply open a web browser with your IP address of the router, you will then be presented with a login prompt. Login with your admin credentials. or from CLI (Command Line interface) type "sh ip port-map" + 0 Votes Reponse To Answer PurpleSkys Moderator January 1, 2013 at 7:46pm PST i would hope that they got it by now, it's only been almost 5 years...please, don't wake the dead + 1 Votes Cisco 2821 Open ports irwandhi January 1, 2013 at 6:52pm PST you can use this command "show control-plane host open-ports" to check what port are opened on your router .. Thanks ..