Troubleshoot DHCP

In this exercise, you troubleshoot DHCP.
Do the following:

1. Run the dhcpdump utility on your server by typing the following
(on one line):
tcpdump -lenx -s 1500 port bootps or port bootpc dhcpdump
2. Generate some DHCP traffic by restarting the network on a client.
3. Review the output of the tcpdump utility.
4. Run the dhcping utility with the respective client, server, and hardware address parameters from a client (on one line):
dhcping -c client_addr -s server_addr -h client_hardware_addr
5. Review the output on the client and the entries in the file
/var/log/messages

Use DHCP and Dynamic DNS

In this exercise, you configure dynamic DNS for your DHCP server.

In part I, you generate a new 128 bit MD5 key.

In part II, you overwrite your DNS configuration file /etc/named.conf with the file named.conf from the Course DVD. You add a key section and allow dynamic updates for the digitalairlines and 10.0.0 zone.

In part III, you configure the DHCP server to update your DNS server.

In part IV, you configure your DHCP client.
Do the following:

■ Part I - Generate a Key
■ Part II - Configure the DNS Server
■ Part III - Configure the DHCP Server
■ Part IV - Configure the DHCP Clients

Part I - Generate a Key

1. Start a terminal emulation from the main menu.
2. Switch to user root by entering su -.
3. When you are prompted for the root password, enter novell.
4. Switch to the directory /var/lib/named/ by entering
cd /var/lib/named
5. To create a key, enter
dnssec-keygen -a HMAC-MD5 -b 128 -n HOST dhcp-dns
The name of the key file is written on the screen by this command. Record it in the space below:
6. Enter cat name_of_the_key.key and record the key in the space below:

Part II - Configure the DNS Server

Do the following:
1. Overwrite your BIND configuration file /etc/named.conf with the file exercises/section_2/named.conf form the 3074 Course DVD.
2. Start your favorite text editor and open the file /etc/named.conf.
3. Append the following after options:
key dhcp-dns {
algorithm HMAC-MD5;
secret your_key;
};
zone "digitalairlines.com" in {
type master;
file "digitalairlines.zone";
allow-update { key dhcp-dns ;}:
};
zone "0.0.10.in-addr.arpa" in {
type master;
file "10.0.0.zone";
allow-update { key dhcp-dns ;}:
};
4. Save the file.
5. Restart your DNS server with the new configuration:
rcnamed restart

Part III - Configure the DHCP Server

Do the following:
1. Open the file /etc/dhcpd.conf with your text editor and enter the following:
ddns-update-style interim;
ddns-updates on;
key dhcp-dns {
algorithm HMAC-MD5;
secret your_key;
}
zone digitalairlines.com. {
key dhcp-dns;
}
zone 0.0.10.in-addr.arpa. {
key dhcp-dns;
}
2. Save the file and close the editor.
3. Switch back to the virtual terminal and enter
chmod 600 /etc/dhcpd.conf
to prevent it from being readable by all users.
4. Close the terminal window.

Part IV - Configure the DHCP Clients

1. On your DHCP client, edit the file /etc/HOSTNAME. Change the hostname of the client to something that is unique in your network and not already known to your DNS server. (For example, you could set your lastname as the hostname of your client.)
2. Restart your dhcpd by entering
rcdhcpd restart

Configure DHCP Clients

In this exercise, you activate the DHCP client with YaST.

To configure a DHCP client, do the following:

1. Start YaST from the main menu.
2. When you are prompted for the root password, enter novell.
3. Select Network Devices > Network Card.
4. Select Change.
5. Make sure that your network card is selected in the top field and
select Edit.
6. Select Automatic Address Setup (via DHCP).
7. Select Host Name and Name Server.
8. Make sure that the following are selected:
❑ Change Host Name via DHCP
❑ Update Name Servers and Search Lists via DHCP
9. Select OK.
10. Select Next.
11. Select Finish.
12. Close the YaST window.
13. Start a terminal emulation from the main menu.
14. Switch to user root by entering su -.
15. When you are prompted for the root password, enter novell.
16. Enter ifstatus-dhcp eth0 to see the IP address of your network
card.
17. Close the terminal window.

Configure the DHCP Server

In this exercise, you install and configure a DHCP server for the domain digitalairlines.com. The IP addresses your DHCP server manages are 10.0.0.101 to 10.0.0.120. Your DHCP server should inform the clients about the DNS information and routers (both services on 10.0.0.254). The computers of two of your neighbors should get the IP addresses 10.0.0.151 and 10.0.0.152. The defaul lease time is one day the maximum lease time two days. Do the following:

■ Part I - Install the DHCP Server Software
■ Part II: Edit the /etc/sysconfig/dhcpd File
■ Part III - Edit the /etc/dhcpd.conf File
■ Part IV - Test the Configuration

Part I - Install the DHCP Server Software

To install the DHCP server software, do the following:

1. Start YaST from the main menu.
2. When you are prompted for the root password, enter novell.
3. Select Software Management.
4. Select the Filter pull-down menu; then select Search.
5. Enter dhcp in the Search text box and click Search.
6. Select the check boxes in front of the following packages:
❑ dhcp
❑ dhcp-server
❑ dhcp-tools
7. Select Accept.
8. When the installation is finished, close all YaST windows.

Part II: Edit the /etc/sysconfig/dhcpd File

To edit the /etc/sysconfig/dhcpd file, do the following:

1. Start a terminal emulation from the main menu.
2. Switch to user root by entering su -.
3. When you are prompted for the root password, enter novell.
4. Start your favorite text editor and open the file
/etc/sysconfig/dhcpd.
5. Change the line
DHCPD_INTERFACE=””
to
DHCPD_INTERFACE=”eth0”
6. Save the file.

Part III - Edit the /etc/dhcpd.conf File

To edit the /etc/dhcpd.conf file, do the following:

1. Start a terminal emulation from the main menu.
2. Switch to user root by entering su -.
3. When you are prompted for the root password, enter novell.
4. Enter ip address show to get the MAC address of your network card.
5. Record your MAC address in the space below:
6. Record the MAC address of your two neighbors in the table below:
Hostname: IP: MAC:
Hostname: IP: MAC:
7. Rename the file /etc/dhcpd.conf to /etc/dhcp.conf.orig by entering
mv /etc/dhcpd.conf /etc/dhcpd.conf.orig
8. Open a new file /etc/dhcp.conf with your favorite text editor.
9. To switch off dynamic DNS updates, enter
ddns-update-style none;
10. To set the default lease time to one day, enter
default-lease-time 86400;
11. To set the maximum lease time to two days, enter
max-lease-time 172800;
12. To define the domain name, enter
option domain-name “digitalairlines.com”;
13. To specify the domain name servers, enter
option domain-name-servers 10.0.0.254;
14. To specify the default gateway, enter
option routers 10.0.0.254;
15. To specify the range of IP addresses to be provided by your DHCP server, enter
subnet 10.0.0.0 netmask 255.255.255.0
{
range 10.0.0.101 10.0.0.120;
}
16. To assign fixed IP addresses to the hosts of two of your neighbors, add
host hostname1.digitalairlines.com
{
hardware ethernet mac1;
fixed-address 10.0.0.151;
}
host hostname2.digitalairlines.com
{
hardware ethernet mac2;
fixed-address 10.0.0.152;
}

Instead of hostname1 and hostname2, enter the hostname of
your neighbor’s computer. Instead of mac1 and mac2, enter the
MAC address of your neighbor’s computer.
17. Save the file.

Part IV - Test the Configuration

To test the configuration, do the following:

1. Enter rcdhcpd syntax-check to test your configuration.

You should get an error message that the lease database could
not be opened. That happens because the dhcpd is not started.
There should be no syntax error in the output of rcdhcpd
syntax-check.

How to Configure Internet Connection Sharing in Windows XP

INTRODUCTION

This article describes how to set up and use the Internet Connection Sharing feature in Microsoft Windows XP. With Internet Connection Sharing, you can use networked computers to share a single connection to the Internet.

How to use Internet Connection Sharing

To use Internet Connection Sharing to share your Internet connection, the host computer must have one network adapter that is configured to connect to the internal network, and one network adapter or modem that is configured to connect to the Internet.

On the host computer

On the host computer, follow these steps to share the Internet connection:
1. Log on to the host computer as Administrator or as Owner.

2. Click Start, and then click Control Panel.

3. Click Network and Internet Connections.

4. Click Network Connections.

5. Right-click the connection that you use to connect to the Internet. For example, if you connect to the Internet by using a modem, right-click the connection that you want under Dial-up.

6. Click Properties.

7. Click the Advanced tab.

8. Under Internet Connection Sharing, select the Allow other network users to connect through this computer's Internet connection check box.

9. If you are sharing a dial-up Internet connection, select the Establish a dial-up connection whenever a computer on my network attempts to access the Internet check box if you want to permit your computer to automatically connect to the Internet.

10. Click OK. You receive the following message:

When Internet Connection Sharing is enabled, your LAN adapter will be set to use IPaddress 192.168.0.1. Your computer may lose connectivity with other computers onyour network. If these other computers have static IP addresses, it is a good idea to set themto obtain their IP addresses automatically. Are you sure you want to enable InternetConnection Sharing?

11. Click Yes.


The connection to the Internet is shared to other computers on the local area network (LAN). The network adapter that is connected to the LAN is configured with a static IP address of 192.168.0.1 and a subnet mask of 255.255.255.0

On the client computer

To connect to the Internet by using the shared connection, you must confirm the LAN adapter IP configuration, and then configure the client computer. To confirm the LAN adapter IP configuration, follow these steps:
1. Log on to the client computer as Administrator or as Owner.

2. Click Start, and then click Control Panel.

3. Click Network and Internet Connections.

4. Click Network Connections.

5. Right-click Local Area Connection, and then click Properties.

6. Click the General tab, click Internet Protocol (TCP/IP) in the This connection uses the following items list, and then click Properties.

7. In the Internet Protocol (TCP/IP) Properties dialog box, click Obtain an IP address automatically (if it is not already selected), and then click OK.

Note: You can also assign a unique static IP address in the range of 192.168.0.2 to 192.168.0.254. For example, you can assign the following static IP address, subnet mask, and default gateway:

IP Address 192.168.0.2 Subnet mask 255.255.255.0 Default gateway 192.168.0.1

8. In the Local Area Connection Properties dialog box, click OK.

9. Quit Control Panel.


To configure the client computer to use the shared Internet connection, follow these steps:
1. Click Start, and then click Control Panel.

2. Click Network and Internet Connections.

3. Click Internet Options.

4. In the Internet Properties dialog box, click the Connections tab.

5. Click the Setup button.

The New Connection Wizard starts.
6. On the Welcome to the New Connection Wizard page, click Next.

7. Click Connect to the Internet, and then click Next.

8. Click Set up my connection manually, and then click Next.

9. Click Connect using a broadband connection that is always on, and then click Next.

10. On the Completing the New Connection Wizard page, click Finish.

11. Quit Control Panel.


When you now start Microsoft Internet Explorer, the client computer will try to connect to the Internet by using the host computer's shared Internet connection.

Troubleshooting

When you turn on Internet Connection Sharing on the host computer, the host computer's LAN adapter is automatically assigned the IP address of 192.168.0.1. Therefore, one of the following situations may occur:
•
IP address conflictEach computer on the LAN must have a unique IP address. If more than one computer has the same IP address, an IP conflict occurs, and one of the network adapters turns off until the conflict is resolved. To resolve this conflict, configure the client computer to automatically obtain an IP address, or assign it a unique IP address.
•
Loss of network connectivityIf your network is configured with a different IP address range than Internet Connection Sharing uses, you will lose network connectivity with the host computer. To resolve this issue, configure the client computers to automatically obtain an IP address, or assign each client computer a unique IP address in the range of 192.168.0.2 to 192.168.0.254.

Reset password administrator

Some program let you reset your administrator password such as ERD Commander, but you have to pay for it. With Windows XP cd lets you reset your administrator for free. See how to do below.
1. Boot from Windows XP cd
2. Until you see Welcome to Setup screen, press Enter to setup Windows
3. The Licensing Agreement screen is shown, press F8 to accept
4. Then you will see an option for repairing you should select your XP installation and press R to repare
5. Don’t do anything and wait until finishing copying files from the cd for installation and windows will restart automatically and Windows is installing.
6. Looking at the lower left side of the screen until you see Installing Devices progress bar, press Shift + F10
7. A prompt is coming up, type NUSRMGR.CPL and press Enter to access your account in Control Panel.
8. It let you change or remove password as you like.
9. Keep installing process…

Ntldr is missing

Ntldr is missing

1. Insert the Windows XP bootable CD into the computer.
2. When prompted to press any key to boot from the CD, press any key.
3. Once in the Windows XP setup menu press the "R" key to repair Windows.
4. Log into your Windows installation by pressing the "1" key and pressing enter.
5. You will then be prompted for your administrator password, enter that password.
6. Copy the below two files to the root directory of the primary hard disk. In the below example we are copying these files from the CD-ROM drive letter "E". This letter may be different on your computer. copy e:\i386\ntldr c:\, copy e:\i386\ntdetect.com c:\
7. Once both of these files have been successfully copied, remove the CD from the computer and reboot.

How to install recovery console

To install the Recovery Console, follow these steps:
1.
Insert the Windows XP CD into the CD-ROM drive.
2.
Click Start, and then click Run.
3.
In the Open box, type d:\i386\winnt32.exe /cmdcons where d is the drive letter for the CD-ROM drive.
4.
A Windows Setup Dialog Box appears. The Windows Setup Dialog Box describes the Recovery Console option. To confirm the installation, click Yes.
5.
Restart the computer. The next time that you start your computer, "Microsoft Windows Recovery Console" appears on the startup menu.

To run the Recovery Console from the Windows XP startup disks or the Windows XP CD-ROM, follow these steps:
1.
Insert the Windows XP startup disk into the floppy disk drive, or insert the Windows XP CD-ROM into the CD-ROM drive, and then restart the computer. Click to select any options that are required to start the computer from the CD-ROM drive if you are prompted.
2.
When the "Welcome to Setup" screen appears, press R to start the Recovery Console.
3.
If you have a dual-boot or multiple-boot computer, select the installation that you must access from the Recovery Console.
4.
When you are prompted, type the Administrator password. If the administrator password is blank, just press ENTER.
5.
At the command prompt, type the appropriate commands to diagnose and repair your Windows XP installation. For a list of commands that are available in Recovery Console, type recovery console commands or help at the command prompt, and then press ENTER. For information about a specific command, type help commandname at the command prompt, and then press ENTER.
6.
To exit the Recovery Console and restart the computer, type exit at the command prompt, and then press ENTER.