How to keep MySQL data secure from internet / firewall?

Problem:
How to use MySQL and be SURE the data is not published to the internet

Setup:
Two PC's and a 4 port router (LinkSys)

One PC will be a MySQL server

Both PC's will be able to access the data.

Will do the basics, eg use user names and passwords.

the most secure method is not to let those two pc's access the internet at all. however, that isn't practical, the people need internet access for other purposes.


questions
1) What are the network port numbers used for MySQL requests?
would like to tell the router NOT to permit data for those ports to be access via the internet connection.

2) can I add a fixed IP address to the MySQL grant permission's table, so that only pc's from the "local" range 192.168.1.* can access the data?
any pc whose IP address is not local should not be granted permission.

(not foolproof, probably some hacker can find a way to spoof ip addresses, but its a start)


3) are there any other ways to secure the data, and make sure it is local?


Thanks in advance!

1) 10061

2) Yes but its a pain in the ass. phpMyAdmin will make it so much easier for you.

3) Block every port at the router level. If you're using a router that uses NAT to share an internet connection you get a sort of defacto firewall for free. Open up only port 80 to your web server and then keep the web server on the internal side.

Don't give my mysql server a default gateway. This will insure no traffic will be sent off the local network. Easy solution