[CentOS] New to CentOS

[Jean Lee]

Hello all,

I 'm new in CentOS 4. I was working before with WBEL 3.0 but I think 
that I was hacked (I'm not sure) so I install a new server.

I want now to be as secure as possible :

- I disabled every services and the command netstat -taupn returns nothing.

- I setup a firewall with iptables which allows only related and 
established connections to the intrenal LAN. I'm sure of this firewall.
Is it better to use ip6tables ?

- I will now update this server. I want to use yum.
Where are placed the CentOS mirrors ( I need it in order to configure 
yum.conf) ?
Is there a way to verify automatically the packages integrity with yum ?

Thank you for your answers

Jean LEE