I have a LAMP setup with Ubuntu 9.10 and want to know if there is one command or the easiest way to simply block all ports on a firewall and open up only the ports that are required for web server functionality. (email, http, etc)

What ports and configurations does everyone have and/or recommend? I'm wanting to limit as many open holes as possible. Thanks.

The ports you need open depends on what you're doing, a LAMP stack you need 80.

Here's a guide to configuring a firewall for debian, which is pretty much the same as ubuntu

http://library.linode.com/networking/se ... bian-lenny

Or, take a look at ufw, which is documented in the Ubuntu Server Guide:

https://help.ubuntu.com/9.10/serverguid ... ewall.html