CIT 500 – Assignment #11
(due Tuesday, December 1)
1. To learn how to configure networking on a Linux system.
2. To learn how to use the various software tools for networks and the Internet services,
including querying the DNS, electronic communication, remote login, file transfer,
remote execution of a command, and reporting status of a remote host
In this assignment, you will use your CentOS virtual machine. Start the lab by editing your VM
settings to configure it to use NAT instead of bridged network, then boot your VM and login.
1. (10 points) What is the IP address and netmask for your virtual machine? Show your
2. (10 points) What are the routes configured on your virtual machine? What is the IP
address of your gateway router? Show your session.
3. (10 points) What are the contents of /etc/hosts? Add kosh.nku.edu with its IP
address (use the host command to look up its IP address) to /etc/hosts. How have
the contents of /etc/hosts changed? Show your session.
4. (40 points) Install Wireshark with the command yum install wireshark-gnome.
Wireshark is a network sniffer and protocol analyzer, a tool that lets you view network
packets and decode them. Once Wireshark is installed, run it as root by typing
To begin sniffing packets, select the Interfaces item from the Capture menu. It will bring
up a dialog box that displays the available network interfaces to sniff. Click on the Start
button on the line for the eth0 interface.
In your terminal, execute the command wget http://www.nku.edu/. If you have
already accessed this web page during this virtual machine session, use a web site other
than www.nku.edu in this command. This command should result in a number of packets
appearing in the Wireshark main window. Click on Stop in the Capture menu.
Examine the packets displayed in the main window. Each line represents one packet.
How many packets were generated by your wget command? What different protocols
are represented in these packets?
Click on the first packet with protocol HTTP to display detailed information about the
packet. Expand the Ethernet layer detail. What are the Ethernet MAC source and
destination addresses of the packet? Expand the HTTP application layer detail. What
are the contents of the packet at this layer? Include both the HTTP command and any
5. (30 points) Edit your Red Hat network configuration files located under
/etc/sysconfig to set your VM to use a static IP address, then restart the network
service. Use the information from the previous two commands to set the correct netmask,
gateway router, and to pick an IP address from your local network range. Include the
contents of both files along with the output of ifconfig eth0 and route as your