OS Security

Here are some links I've used many times to secure and harden my servers. They're for CentOS v.5.7.

-Hardening procedures.-
http://wiki.centos.org/HowTos/OS_Protection

-Default services-
http://www.cyberciti.biz/faq/linux-default-services-which-are-enabled-at-boot/

-Iptables-
http://wiki.centos.org/HowTos/Network/IPTables