On 2013-12-02, Robert Clove <cloverobert at gmail.com> wrote: > I was searching around but was not able to find out. > We all know that packet traverses through the Net Filter hooks but how to > practically realize that. It's not really clear what you are asking. Are you just looking for general documentation? http://netfilter.org/ CentOS-specific docs? https://access.redhat.com/site/documentation//en-US/Red_Hat_Enterprise_Linux/6/html/Security_Guide/sect-Security_Guide-Firewalls.html Something more specific? If so, please give real details so people can give you real help. --keith -- kkeller at wombat.san-francisco.ca.us