In the last chapter, we covered IPv4, IPv6, client-side DNS, and network troubleshooting. We worked with IPv4 and discussed IPv4 routing, and then we did the same for IPv6. This led into client-side DNS and network troubleshooting; we covered a number of command-line tools that assist in troubleshooting potential network connectivity issues.
In this chapter, we will focus on security: host security, SSH, and encryption. First, we will cover host security; the /etc/sudoers, /etc/hosts.allow, and /etc/.hosts.deny files will be our main focus. Next, we will work with SSH. We will focus on the steps involved in setting up SSH, and the steps for generating a key. We will also look at logging in to a remote system using SSH. Additionally, we will work with the various SSH files that are available to us. Encryption will be our next focal point...