Chapter 12 Study Guide

Network Configuration

Networks

Be sure to have a basic understanding of local area networks and wide area networks, and their components.

IPv4

• Consists of four octets. Each octet represents an 8-bit binary number(0-255). Ex: 192.168.1.1
• 32 bit address(4 octets = 4 x 8 = 32)
• Subnet mask is used to determine the host portion of the IP address.
• Default Gateway directs traffic destined to other networks(LANs). Ex: to the internet.

IPv6

• Uses 128 bits. Capable of supplementing 340 trillion trillion trillion IP addresses.
• No subnetting required due to an abundance of address space.
• First half of address represents your network. Second half uniquely identifies computers on the LAN(link local).

Configuring a Network Interface

• NIC(Network Interface Controller) drivers are usually contained within modules that can be inserted to the Linux kernel.
• Modules end with the .ko(kernel object) extension and are typically stored in /lib/modules directory.
• Use insmod or modprobe commands to manually load modules into the Linux kernel.
• Use lsmod or rmmod commands to remove a module from the Linux kernel.
• Configure the loaded module driver for the NIC using the ifconfig(interface configuration) command.
• dhcpclient eth0 command configures a NIC for dynamic host configuration protocol.
• To show interface statistics use ifconfig or netstat -i.
• The ifdown eth0 and ifup eth0 commands can be used to deactivate and active the network interface, respectively.
• The ping command is used to test network connectivity.
• All configuration options can also be achieved through a GUI within the Network Configuration tool.

Useful Commands

insmod
modprobe
lsmod
rmmod
ifconfig
netstat
ifdown
ifup
dhcpclient
ping

Name Resolution

• Set a host name using the hostname command.