IT 1100 : Introduction to Operating Systems

Chapter 14

Network Settings

Every machine must have a unique IP on the network. The IP identifies all computers.

DHCP - Dynamic Host Configuration Protocol

Static IP - Static IP Configuration



Domain Name Servers - (DNS)

Network Configuration

During the installation process we set up the Network configuration for our computers - but sometimes we need to see what that configuration is or we need to change it due to a typo or a change in our network.

To view your current configuration in Command Line Install, use either of these commands:

An easy way to change the IP address of your Linux computer is from the terminal (use the IP address that works with your VLAN):

NOTE: eth0 represents the interface. Use ifconfig to locate the proper interface for your system.

To change the gateway, use this command:

You may also change the address from the interfaces file, by editing it with the VI editor:

Note: The Ubuntu GUI installation does not store its network configuration in the /etc/network/interfaces file. However, the ifconfig command works in all installs.

After changing the IP address, restart the network interface by typing: - sudo service network-manager restart

Another way: after changing the IP address, restart the network interface by typing: - sudo ifdown eth0; sudo ifup eth0

Package Management

Installing Packages (Software) - requires sudo permissions

Linux packages have the following extensions:

apt is a debian based program.

Remember that apt is an upgraded version of apt-get. It also includes apt-cache in the upgrade. You can choose to use the generic apt or to specify apt-get and apt-cache.

To search for possible software to install, in Ubuntu, we use the apt-cache program with the following format:

sudo apt-cache search game | less

apt searches the repository for the package or program and installs it. Using apt-get to install or upgrade will install/upgrade all required packages for the particular program you’ve chosen.

apt-get update will update the list of available programs to install. It doesn’t actually update any programs. It doesn’t hurt to always update before installing just in case.

apt-get install <name> will install a program. apt install <name>

apt-get upgrade will update the program specified.

To show all the packages installed using apt

To install an individual package or program you’ve downloaded.

To list all the installed packages

yum is similar to apt it is a redhat based command

yum install <name>


Repositories are a collaboration of the work of many programmers. It is a combination of the Linux kernel, plus the Ubuntu distribution software, plus extra programs and packages. Repositories store this software in such a way that when we request updates to our current installation we only get the new files that need updating and don’t have to re-download all files in our system.

The Ubuntu repository components are:

Our repository url’s are stored at /etc/apt/sources.list

Textbook Time

Textbook reading is optional. It describes package management and repositories in detail.

Last Updated 12/15/2017