Lesson 1

This course expands on basic UNIX system administration by covering the fundamentals of UNIX network administration.
Furthermore, the course focuses on

1. TCP/IP networking under UNIX,
2. network monitoring, and
3. debugging.

The course also covers the variations between the Solaris, Linux, AIX, and HP-UX operating systems.
The examples and exercises, however, focus on using a Linux or a Solaris system. In cases where the commands or procedures vary significantly between Linux and Solaris, two versions of examples and exercises are offered.One course is for Linux and the other for Solaris.

A Linux administrator should understand the following core concepts:

1. Operating System Fundamentals: knowledge of the Linux file system hierarchy, process management, and system startup and shutdown.
2. File System Management: understanding of disk partitioning, file system types, and creating, mounting, and unmounting file systems.
3. Package Management: knowledge of using package managers such as apt, yum, or dnf to install, update, and remove software packages.
4. Network Configuration: ability to configure and manage network interfaces, routing, firewall rules, and network services such as DHCP, DNS, and NTP.
5. Security: understanding of basic security concepts like permissions, user and group management, file and directory security, and security-enhancing tools like SELinux.
6. System Monitoring: knowledge of using tools like top, ps, df, and free to monitor system performance, and knowledge of log files and system event logs.
7. Bash scripting: ability to write shell scripts to automate tasks and perform operations on large groups of systems.
8. Virtualization: understanding of virtualization technologies such as KVM, Xen, and VMware, and the ability to create, manage, and monitor virtual machines.
9. High Availability: knowledge of concepts and tools used to achieve high availability such as clustering, load balancing, and failover.

After completing the course, you will be able to:

1. Describe in general terms the different layers in the TCP/IP protocol
2. Understand the rules governing IP address classes and netmasks
3. Configure the resolver library to arrange for TCP/IP name service
4. Bring interfaces up and down, and set their IP addresses and netmasks
5. Set the default route in the kernel routing table
6. Describe the difference between TCP and UDP services
7. Understand the significance of the /etc/services file and well-known port numbers
8. Configure the inet daemon, which controls many Internet services
9. Briefly describe many common services, and use telnet to contact servers directly
10. Use the ping command to test network connectivity
11. Use the netstat command to examine kernel tables pertaining to networking
12. Use the traceroute command to discover network paths
13. Use tcpdump to examine all network traffic

The TCP/IP Protocol has played an essential role in the development of the internet. It may very well be argued that without the the seven layers of the OSI model, the internet may never have come into existence.