Emmett Dulaney

GPG includes the tools you need to use public key encryption and digital signatures on your Linux system. You can figure out how to use GPG gradually as you begin using encryption in Linux. The information you find here shows some of the typical tasks you can perform with GPG to protect your Linux system. How to Generate the key pair with GPG in Linux The steps for generating the key pairs are as follows: Type gpg --gen-key.

The Linux kernel has built-in packet filtering software in the form of something called netfilter. You use the iptables command to set up the rules for what happens to the packets based on the IP addresses in their header and the network connection type. To find out more about netfilter and iptables, visit the documentation section of the netfilter website.

Like any other OS, Linux needs to be protected with a firewall. A firewall is a network device or host with two or more network interfaces — one connected to the protected internal network and the other connected to unprotected networks, such as the Internet. The firewall controls access to and from the protected internal network.

One important aspect of securing the host is protecting important system files — and the directories on your Linux system that contain these files. In Linux, you can protect the files through file ownership and the permission settings that control who can read, write, or (in the case of executable programs) execute the file.

Linux comes with the GNU Privacy Guard (GnuPG or GPG) encryption and authentication utility. With GnuPG, you can create your public and private key pair on your Linux system, encrypt files with your key, and digitally sign a message to authenticate that it’s from you. If you send a digitally signed message to someone who has your public key, the recipient can verify that you signed the message.

The first step in securing your Linux system is setting up a security policy — a set of guidelines that states what you enable users (as well as visitors over the Internet) to do on your Linux system. The level of security you establish depends on how you use the Linux system and on how much is at risk if someone gains unauthorized access to your system.

In Linux systems, you can use the tar command to archive files to a device, such as a hard drive or tape. The tar program in Linux creates an archive file that can contain other directories and files and (optionally) compress the archive for efficient storage. Then the archive is written to a specified device or another file.

It is easy to share files between Linux computers on a local network. The Linux way of accomplishing this is to utilize NFS (Network File System). Sharing files through NFS is simple and involves two basic steps: On the Linux system that runs the NFS server, you export (share) one or more directories by listing them in the /etc/exports file and by running the exportfs command.

As a Linux system administrator, you may have to run some programs automatically at regular intervals or execute one or more commands at a specified time in the future. Your Linux system includes the facilities to schedule jobs to run at any future date or time you want. You can also set up the system to perform a task periodically or just once.