Fbsd gateway+restrictions

[Dead Line]

Hello Everybody,


    I have a DSL Router <--connected--> internet <--connected--> FreeBSD 
4.8-R box
    And this FBSD connected to a Hub which connected to around 20 PC's 
(Win98+XP) on a LAN.
    Easy? its just a DSL LAN.

1)
    I want This Box to work as a Internet gateway, and to share the internet 
between the PC'S
    thro this box.
    shall i just enable the gateway enable 'yes' ? only? it will share the 
net to?

2) How can i do restrictions on  the LAN? for example, I want to give this 
specific IP an Internet
    connection, and i want to block that one.

3) I want to allow this specific IP to have downloads enables, and other IP, 
no downloads.

4) Also can i setup a timing ? to give internet connection from this time to 
that time per day?

   Thank you a much, any ideas will be really appreciate it.

   Marwan.

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