OPS235 Lab 8 - Fedora17
Contents
- 1 Install and Configure a DHCP Server
- 1.1 Overview
- 1.2 Objectives
- 1.3 Required Materials (Bring to All Labs)
- 1.4 Prerequisites
- 1.5 Linux Command Online Reference
- 1.6 Resources on the web
- 1.7 Lab Preparation
- 1.8 Completing the Lab
- 1.8.1 Investigation 1: How do you install the DHCP Server?
- 1.8.2 Investigation 2: What configuration options and directives need to be set in dhcpd.conf?
- 1.8.3 Investigation 3: How do I configure dhcpd settings to be applied to all subnets?
- 1.8.4 Investigation 4: How do I configure dhcpd to provide IP configuration to my virtual network?
- 1.8.5 Investigation 5: How do I test my dhcpd service on my virtual network?
- 1.8.6 Investigation 6: Where does the dhcp server store a record of leased addresses?
- 1.8.7 Investigation 7: How can I lease the same address every time?
- 1.9 Completing the lab
- 1.10 Preparing for the Quizzes
Install and Configure a DHCP Server
Overview
- In this lab, you will learn how to setup, and run a DHCP server on your f16host machine, and then test-out the DHCP server by booting your VMs to receive IP addresses from the DHCP server.
Objectives
- To install, configure, and test ISC's DHCP Server.
- To obtain log information from DHCP server including lease address information.
- To lease the same IP address every-time from VM boot-up (instead of having DHCP server randomly assign IP address).
Required Materials (Bring to All Labs)
- Fedora 16 LIVE CD - You can burn this onto a CD-R in the Open Lab
- Fedora 16 x_64 Installation DVD - You can burn this onto a DVD-R in the Open Lab (or burn image onto a DVD+R if you are using the Freedom Toaster).
- SATA Hard Disk (in removable disk tray)
- USB Memory Stick (minimum 64M)
- Lab Logbook (Lab5 Reference Sheet) (to make notes and observations).
Prerequisites
- Completion and Instructor "Sign-off" of Lab 6: OPS235 Lab 7
Linux Command Online Reference
Each Link below displays online manpages for each command (via http://linuxmanpages.com):
Networking Utilities / Files: | Additional Utilities: |
Resources on the web
Additional links to tutorials and HOWTOs:
- man pages for dhcpd, dhcpd.conf, dhcpd.leases, dhcp-options, dhclient, dhclient-conf
- Fedora DHCP Configuration Guide
- Internet Software Consortium DHCP page
Lab Preparation
Completing the Lab
Investigation 1: How do you install the DHCP Server?
- To check that you have
dhclient
installed, enter the command:
-
rpm -q dhclient
-
- If the package is not installed, you will get the message "package dhclient is not installed", otherwise, you will get the version information of the rpm package. Install the
dhclient
package if it was not installed. - Check to see if the
dhcp
server package is installed. - Follow the normal procedure to install the DHCP server rpm package called
dhcp
usingyum
. - Enter the command to list all the files installed from the DHCP server package.
- What file appears to be a sample configuration file?
- Copy the sample
dhcpd.conf
file to the/etc/dhcp
directory making sure it is named/etc/dhcp/dhcpd.conf
Answer the Investigation 1 observations / questions in your lab log book.
Investigation 2: What configuration options and directives need to be set in dhcpd.conf?
- Study the man pages of
dhcpd
,dhcpd.conf
,dhcp-options
, anddhcpd.leases
and make notes in your log book. In particular, look up the meaning and possible value(s), if any, for the following configuration options:
-
broadcast-address
-
default-lease-time
-
max-lease-time
(How is this different fromdefault-lease-time
?) -
domain-name
-
domain-name-servers
-
fixed-address
-
group
-
hardware
-
host
-
host-name
-
range
-
routers
-
subnet
-
subnet-mask
-
- Study the sample
dhcpd.conf
file to see examples of how these options are used.
Answer the Investigation 2 observations / questions in your lab log book.
Investigation 3: How do I configure dhcpd settings to be applied to all subnets?
- Edit
/etc/dhcp/dhcpd.conf
and examine the top section of the file. - Make the following changes to the global settings:
-
domain-name
should be set to ops235.org -
domain-name-servers
should be set to 192.168.235.1 -
default-lease-time
should be set to 20 minutes -
max-lease-time
should be set to 1 hour
-
- Save and exit your editing session.
Answer the Investigation 3 observations / questions in your lab log book.
Investigation 4: How do I configure dhcpd to provide IP configuration to my virtual network?
- Edit
/etc/dhcp/dhcpd.conf
for a second time, and add a new subnet delcaration for your virtual network - The network address is 192.168.235.0/255.255.255.0 and the range of host addresses should be from 51 to 60
- Also add a default gateway for the virtual network of 192.168.235.1
- Save your editing session, and exit the text editor.
- Open another terminal window (ssh into fedora3 from fedora host as user root) and issue the following command:
-
tail -f /var/log/messages
-
- This will show you the last 10 lines of
/var/log/messages
continue to display new lines as they are added to the log. - In your original terminal prompt attempt to start the
dhcpd
service. - You should see new lines being added to the messages file.
- If the
dhcpd
service fails to start any error messages will be logged in the messages file. Read the errors and attempt to fix your configuration file. - If the
dhcpd
service starts successfully you should see success messages in the log. - If your
dhcpd
service starts successfully, try to generate errors by editing the configuration file and introduce an error by removing a semicolon or closing curly bracket. - Restart your
dhcpd
service and observe the error messages generated. This is good practice to learn how to trouble-shoot and solve dhcpd errors. - Make certain that you have corrected those errors, and that your dhcpd service works properly.
Answer the Investigation 4 observations / questions in your lab log book.
Investigation 5: How do I test my dhcpd service on my virtual network?
- On a fedora3 terminal window make sure that the command
tail -f /var/log/messages
is running. - On your fedora2 VM, change the configuration of em1 (or your interface name) to receive dynamic address configuration.
- Save your changes and restart the
NetworkManager
service. - Observe the messages that get logged. You should see output similar to the following:
<span style="background-color:yellow"> Mar 24 13:28:24 fedora3 dhcpd: DHCPDISCOVER from 52:54:00:61:00:e7 via eth2 Mar 24 13:28:25 fedora3 dhcpd: DHCPOFFER on 192.168.235.51 to 52:54:00:61:00:e7 via eth2 Mar 24 13:28:25 fedora3 dhcpd: DHCPREQUEST for 192.168.235.51 (192.168.235.13) from 52:54:00:61:00:e7 via eth2 Mar 24 13:28:25 fedora3 dhcpd: DHCPACK on 192.168.235.51 to 52:54:00:61:00:e7 via eth2</span>
- On fedora2 confirm the IP address assignment using
ifconfig
Answer the Investigation 5 observations / questions in your lab log book.
Investigation 6: Where does the dhcp server store a record of leased addresses?
- If your fedora3 DHCP server successfully issued the proper IP address configuration values to fedora2, check the file called
/var/lib/dhcpd/dhcpd.leases
- You should see contents similar to:
lease 192.168.235.51 { starts 3 2010/03/24 17:28:25; ends 3 2010/03/24 17:48:25; cltt 3 2010/03/24 17:28:25; binding state active; next binding state free; hardware ethernet 52:54:00:61:00:e7; }
- On the client fedora2 check the contents of the
/var/lib/dhclient
directory. The files in this directory is where the dhclient stores its record of leases.
Answer the Investigation 6 observations / questions in your lab log book.
Investigation 7: How can I lease the same address every time?
- Make certain that you are located in your fedora3 virtual machine.
- Create a host declaration for fedora2. Make sure you record the correct
hardware ethernet
setting that corresponds to the MAC address of the interface in fedora2. - Give it the fixed-address 192.168.235.12
- Start your service and test the address assignment by releasing your current address on fedora2 and then requesting a new address. Use the following commands on fedora2:
-
dhclient -r eth1
-
dhclient eth1
-
- Confirm that you received the fixed address you were supposed to.
Answer the Investigation 7 observations / questions in your lab log book.
Completing the lab
Arrange proof of the following on the screen:
- DHCP server log file showing a lease occuring
- DHCP server configuration file showing subnet and host declaration
- DHCP server lease file
- DHCP client lease file
Preparing for the Quizzes
- What protocol and port does dhcp use?
- What file is used to configure dhcpd?
- Can a dhcp server also be a dhcp client?
- What is the difference between max-lease-time and default-lease-time?
- What unit of measurement does default-lease-time require?
- What dhcp option is used for configuring a default gateway?
- What is the parameter range in the DHCP server configuration file used for?
- What is the purpose of a dhcp relay agent?
- Why might a dhcp relay agent be required?