Configuring IPv6
15. Delete the address you just added with the netsh command. Use the following syntax
netsh interface ipv6 delete address interface=lan address=2001:
ab1:442e:1323::7
If you have any issues deleting the address, try using a nontruncated number. The equivalent for this address would be:
2001:0ab1:442e:1323:0000:0000:0000:0007
16. Reset the GUI IPv6 Properties dialog box by selecting Obtain an IPv6 address auto- matically. If you wish, run an ipconfig to find out your auto-assigned address and another computer’s address. Try pinging those addresses as well.
Lots more information about configuring IPv6 can be found at the Microsoft TechNet.
Figure 4-17 IPv6 GUI configuration
Figure 4-18
Ipconfig/all results of added IPv6 address
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DEFINING THE DUAL IP STACK
A dual IP stack exists when there are two Internet Protocol software implementations in an operating system, one for IPv4 and another for IPv6. Dual stack IP hosts can run IPv4 and IPv6 independently, or they can use a hybrid implementation, which is the most commonly used method for modern operating systems.
Dual stack TCP/IP implementations enable programmers to write networking code that works transparently on IPv4 or IPv6. The software can use hybrid sockets designed to accept both IPv4 and IPv6 packets. When used in IPv4 communications, hybrid stacks use IPv6 methodologies but represent IPv4 addresses in a special IPv6 address format known as the IPv4-mapped address.
IPv4-mapped addresses have the first 80 bits set to 0 (note the double colon), the next 16 set to 1 (shown as ffff ), and the last 32 bits populated by the IPv4 address. These addresses look like IPv6 addresses, other than the last 32 bits, which are written in the customary dot- decimal notation. Here is an example:
::ffff:10.254.254.1
This is an IPv4-mapped IPv6 address for the IPv4 address 10.254.254.1.
DEFINING IPv4 TO IPv6 TUNNELING
IPv6 packets can be encapsulated inside IPv4 datagrams. This is known as IPv6 tunneling, or IP 6 to 4. In Microsoft operating systems, this is generally done with the Teredo adapter, which is a virtual adapter or “pseudo-interface,” not a physical network adapter. This allows connectivity for IPv6 hosts that are behind an IPv4 device or IPv6 unaware device. It ensures backward compatibility. An example of one of these addresses would be:
Fe80::5efe:10.0.0.2%2
Notice that this is a link-local address and that the IPv4 address (10.0.0.2) is actually part of the whole IPv6 address. IPv6 tunneling requires little router configuration and no client computer configuration whatsoever, so it is fairly easy to implement, enabling IPv6 clients to interact with IPv6 servers on the Internet, even though the router is not IPv6 aware.
S K I L L S U M M A R Y
INTHISLESSON, YOULEARNED:
• How to categorize IPv4 addresses using classifications such as Class A, B, and C.
• What the default gateway and DNS server are and how to configure them within a network adapter’s TCP/IP properties dialog box.
• How to define advanced TCP/IP concepts, such as NAT and subnetting, and how to create a subnetted network.
• How to define CIDR.
• The basics of IPv6 and how to configure IPv6 in the command line.
• How to define IPv6 dual stack and tunneling technologies.
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94 | Lesson 4
Multiple Choice
Circle the letter that corresponds to the best answer.
1. Your client requires that you install 284 computers on a single IP network. Which of the following IP classes would be your best option?
a. Class A b. Class B c. Class C d. Class D
2. Your boss wants you to set up three computers on a classful network with a default sub- net mask of 255.0.0.0. What class does he want the computers to be set up on?
a. Class A b. Class B c. Class C d. Class D
3. Proseware, Inc., needs you to set up 100 computers on a private Class A network. Which of the following IP network numbers meet all of the criteria for a private Class A net- work?
a. 100.10.1.0 b. 192.168.1.0 c. 172.16.0.0 d. 10.0.0.0
4. You need to subnet a 192.168.1.0 network. You decide to use the 255.255.255.240 sub- net mask. What is 240 equal to in binary?
a. 11100000 b. 11000000 c. 11110000 d. 10000000
5. The IT director has asked you to set up 14 separate IP networks that can each have up to 400 computers. What IANA private IP range should you select?
a. 10.0.0.0–10.255.255.255 b. 172.16.0.0–172.31.255.255 c. 192.168.0.0–192.168.255.255 d. 169.254.0.0–169.254.255.255
6. You are troubleshooting a computer that cannot obtain the proper IP address from a DHCP server. When you run an ipconfig/all, you see that the computer has obtained the address 169.254.67.110 automatically. What has occurred? (Select the best answer.) a. The DHCP server has auto-assigned an IP address to the computer.
b. APIPA has auto-assigned an IP address to the computer.
c. A SOHO router has auto-assigned an IP address to the computer.
d. The ISP has auto-assigned an IP address to the computer.
7. You need to connect 802.11a, 802.11b, and 802.11n wireless networks together. What wireless tool will guarantee connectivity between these networks?
a. Wireless network adapter b. Wireless hub
c. Wireless router d. Wireless bridge
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Knowledge Assessment
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8. Your boss’s computer cannot connect to the Internet. Examine the following ipconfig results and select the best answer explaining why this has occurred.
IPv4 Address ... : 10.254.254.1 Subnet Mask ... : 255.255.255.0 Default Gateway... : 10.254.254.255 a. The subnet mask is incorrect.
b. The IP address is incorrect.
c. The default gateway is incorrect.
d. The subnet mask and the IP address are incorrect.
9. A user cannot connect to any Web sites. Review the ipconfig results that follow and select the best answer explaining why this has occurred.
Windows IP Configuration
Host Name ... : Computer1 Primary Dns Suffix ... :
Node Type ... : Hybrid IP Routing Enabled... : No WINS Proxy Enabled ... : No Ethernet adapter lan:
Connection-specific DNS Suffix.:
Description ... : Intel(R) 82566DC-2 Gigabit Network Connection
Physical Address ... : 00-1C-C0-A1-55-16 DHCP Enabled ... : No
Autoconfiguration Enabled ... : Yes
IPv4 Address ... : 10.254.254.105(Preferred) Subnet Mask ... : 255.255.255.0
Default Gateway ... : 10.254.254.1 DNS Servers ... : 10.255.254.1 a. The MAC address is incorrect.
b. The DNS server address is incorrect.
c. The default gateway address is incorrect.
d. The computer has no IP address.
10. You have installed a device that has two IP addresses. One address, 64.51.216.27, is displayed to the Internet. The other address, 192.168.50.254, communicates with the LAN. What type of technology have you implemented?
a. Subnetting b. IPv6
c. Network address translation d. Class A public IP address
Fill in the Blank
Fill in the correct answer in the blank space provided.
1. The manager of IT asks you to subnet a group of computers on the 192.168.50.0/28 network. This will provide you with ____________ number of subnets.
2. You have configured IP network 192.168.1.0 with the subnet mask 255.255.255.240.
Two computers have the IP addresses 192.168.1.113 and 192.168.1.114. Another
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computer cannot communicate with them. That computer is using the IP address 192.168.1.145. Here, the third computer cannot communicate with the others because it is on Subnet ID ____________.
3. Your network uses the subnetted IP network 192.168.100.0/26. Its subnet mask is ____________.
4. You are troubleshooting an IP network with the following number: 10.254.254.0/24.
This type of IP network number is known as ____________.
5. Your boss worries about how many IPv4 addresses are left and inquires about installing IPv6. Whereas IPv4 is a 32-bit system, IPv6 is a ____________ -bit system.
6. A client wants you to set up a group of IPv6 network interfaces in such a way that each of them will have all packets delivered to them. Here, you should implement a ____________ address.
7. You are troubleshooting a server that needs to connect directly to the Internet. After you run an ipconfig/all, you see that the server has been auto-assigned the IPv6 address fe80::260:8ff:fec0:98d%4. The server won’t connect to the Internet due to the fact that this is a ____________ address.
8. To save time when working with IPv6 addresses in the command line, you like to trun- cate them. The truncated version of 2001:4860:0000:2001:0000:0000:0000:0068 would be ____________.
9. You see an IPv6 address displayed as fe80::5efe:10.0.0.2%2. This is an example of ____________.
10. You are troubleshooting a client’s network. The client is using the following IP network scheme:
IP network: 192.168.50.0 Subnet mask: 255.255.255.240
The client has 196 computers that are functioning properly, but another 30 computers will not connect to the network. This is because ____________.
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