Part 2: Adding the firewall rules

In part two of this series we’re going to discuss adding firewall rules to the router.  Everyone knows that adding ingress (or incoming) firewall rules is important to securing your network.  However, the same can be said for adding egress rules for traffic leaving your network.  For instance, aside from an email server, no client should ever send traffic to the Internet via TCP port 25.  If you see

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Setting up NAT with CentOS/Red Hat 6

​This will be part 1 in a series of configuring CentOS/Red Hat 6 as a secured firewall. Though I am a huge fan of pfSense (which can be found here pfSense), I wanted to build my own from scratch. So, the first part of this series will consist of setting up PAT (or NAT overload for the Cisco geeks) on Linux. The first step is to configure the network cards. 

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RHEL/CentOS Server Security

As a part of the sys admin’s job, it is important to take a few extra minutes to go through and properly secure a newly installed Linux server. These steps include enabling SELinux on the machine, configuring the firewall, and setting user permissions. There are however additional steps one should take in order to secure their server. One would be to tune and secure kernel parameters, set limits on

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GPG Keys

​GnuPG is used to encrypt and sign email messages and files. First you need to create the GPG key: Generating Keys ———————————————————– $ gpg –gen-key ———————————————————– Select option 5 for RSA and then type the encryption level. ———————————————————– Please select what kind of key you want: (1) DSA and Elgamal (default) (2) DSA (sign only) (5) RSA (sign only) Your selection? 5 RSA keys may be between 1024 and 4096 bits

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