How to open and close ports?

Question

how do you open and close ports on a firewall and a router?

Answer 1

The exact instructions will vary by router make/model.  Here are instructions for opening ports on the Linksys WRT54G (other routers should have similar options for port forwarding).  Login to your router (open browser to http://192.168.1.1 and enter the password).  Click Applications & Gaming in the menu.  On the Port Range Forward tab, type a name for the application, this can be whatever you want.  Then enter the port range you want forwarded (aka = open) in the Start and End boxes.  Enter the IP Address* of the computer you want the ports forwarded to.  Check Enable (You would simply uncheck enable if you ever wanted to close these ports in the future).  Then scroll down and click Save Settings.

Now traffic directed to those ports will be forwarded to the computer specified by the ip address you entered.  You'll also want to make sure  that another software firewall is not blocking those ports on the computer specified by the ip address you entered.  For example, if you have Windows firewall, ZoneAlarm, Norton security suite, etc. there is a chance they are also blocking the port and you will need to open those up as well.

Routers by default will have most ports closed.  This is part of the firewall feature built into your router.  If you want to verify which ports are open on your router try Shields Up! at this url:

https://www.grc.com/x/ne.dll?bh0bkyd2

Good Luck!  

*You can get your ip address by going to Start > Run > Type "cmd" (without the quotes).  At the command prompt type "ipconfig".  It will display the IP address.  For example,

IP Address. . . . . . . . . . . . : 192.168.1.101