Identify each hop (router) between two systems using the tracert

3. Identify each hop (router) between two systems using the tracert

command.

4. Verify DNS configuration using the nslookup command. Using ipconfig with the /all switch shows you the IP configuration of the

computer. If the IP address is invalid, communication might fail. If the subnet mask is incorrect, the computer has an incorrect Network ID and therefore communication might fail, especially to remote subnets. If the default gateway is incorrect or missing, the computer is not able to communicate with remote subnets. If the DNS server is incorrect or missing, the computer might not be able to resolve names and communication might fail.

If the computer is set to accept a DHCP server and one does respond, the computer uses Automatic Private IP Addressing (APIPA), which generates an IP address in the form of 169.254.xxx.xxx and the subnet mask of 255.255.0.0. After the computer generates the address, it broadcasts this address until it can find a DHCP server. When you have an Automatic Private IP Address, you can only communicate with computers on the same network/subnet that has an Automatic Private IP Address.

If you can successfully ping an IP address but not the name, name resolution is failing. If you successfully ping the computer name but the response does not resolve the FQDN name, resolution has not used DNS. This means a process such as broadcasts or WINS has been used to resolve the name, and applications that require DNS might fail. If you encounter a Request Timed Out message, this indicates that there is a known route to the destination computer but one or more computers or routers along the path, including the source and destination, are not configured correctly. A Destination Host Unreachable message indicates that the system cannot find a route to the des- tination system and therefore does not know where to send the packet on the next hop.

Tools to Help Diagnose Network Problems

Cram Quiz

1. What command would you use to release the IPv6 address handed out by a DHCP server?

❍ A. ipconfig /all ❍ B. ipconfig /release ❍ C. ipconfig /release6 ❍ D. ipconfig /flushdns

2. What command can you use to query a DNS server for a name translation to an IP address?

❍ A. ipconfig ❍ B. ipconfig /flushdns ❍ C. ipconfig /registerdns ❍ D. nslookup

Cram Quiz Answers

1. C is correct. The ipconfig /release6 command releases the IPv6 address configured by a DHCP server. Answer A is incorrect because the ipconfig /all command only displays the IP configuration. Answer B is incorrect because the ipconfig /release command releases IPv4 addresses. Answer D is incorrect because the ipconfig /flushdns clears out the local DNS cache on a Windows system.

2. D is correct. The nslookup command displays information that you can use to diagnose your DNS infrastructure. Answer A is incorrect because the ipconfig command only displays IP configuration. Answer B is incorrect because the ipconfig /flushdns command clears out the local DNS cache on a Windows system. Answer C is incorrect because the ipconfig /regis- terdns registers a system with a DNS server.

CHAPTER 5: Configuring Windows Networking

Review Questions

1. What command would you use to renew the DHCP IPv4 addresses?

❍ A. ipconfig ❍ B. ipconfig /renew ❍ C. ipconfig /renew6 ❍ D. ipconfig /release_and_renew ❍ E. ipconfig /registerdns

2. What command would you use to flush the DNS cache stored on an individual Windows 7 machine?

❍ A. ipconfig ❍ B. ipconfig /renew ❍ C. ipconfig /renew6 ❍ D. ipconfig /registerdns ❍ E. ipconfig /flushdns

3. What command can be used to show network connectivity to a computer?

❍ A. ipconfig ❍ B. arp ❍ C. ping ❍ D. traceroute

4. If you want to show IP addresses and their corresponding MAC addresses, what command would you use?

❍ A. ipconfig ❍ B. ipconfig /all ❍ C. arp ❍ D. ping ❍ E. tracert

5. You are trying to figure out why a computer cannot connect to a file server. You type in ipconfig and you get the following output:

C:\Users\User>ipconfig Windows IP Configuration Ethernet adapter Local Area Connection:

Connection-specific DNS Suffix . : acme.com. Link-local IPv6 Address . . . . . : fe80::35d3:1958:365b:380a%13 IPv4 Address. . . . . . . . . . . : 169.254.3.103

Review Questions

Subnet Mask . . . . . . . . . . . : 255.255.0.0 Default Gateway . . . . . . . . . :

What is the problem?

❍ A. The computer cannot connect to the DHCP server to get an address. ❍ B. The server was not assigned a default gateway. ❍ C. The subnet mask is wrong. ❍ D. You cannot determine the problem from this example.

6. You can ping a PC using an address but not by name. What is the problem?

❍ A. You are not on the same subnet as the computer. ❍ B. A firewall is blocking access to the computer by name. ❍ C. You need to start the DHCP client service on your PC. ❍ D. You have a DNS name resolution problem.

7. You work as the desktop support technician at Acme.com. You want to assign an address to a computer that will be available on the Internet and it will have the same address for both IPv4 and IPv6. What kind of address is this?

❍ A. A unique private address ❍ B. A multicast local address ❍ C. A site-local address ❍ D. A global unicast address

8. You work as the desktop support technician at Acme.com. You have a user that works between the Sacramento and New York offices. She currently has a static IP addresses assigned to her computer. When she is at the Sacramento office, her system has no problem connecting to the network. When she travels to New York, her system cannot connect to the network. What is the problem?

❍ A. You need to update the drivers for the network card. ❍ B. You need to assign a Public IPv4 address. ❍ C. You need to run the troubleshooting wizard. ❍ D. Within the TCP/IPv4 Properties dialog box, you need to select the

Obtain an IP address automatically option. 9. You are assigned a computer to test the IPv6 address of Server01. What com-

mand would you use?

❍ A. ping –s server01 ❍ B. ping –6 server01 ❍ C. ping –a server01 ❍ D. ping –t server01

CHAPTER 5: Configuring Windows Networking

10. Which type of IPv6 address is automatically configured and is used to communi- cate with local network devices such as a neighboring router?

❍ A. Global unicast address ❍ B. Unique local unicast address ❍ C. Link-local address ❍ D. Anycast address

Review Question Answers

1. Answer B is correct. To renew IPv4, you have to use the ipconfig /renew command. Answer A is incorrect because the ipconfig command without any options only displays basic IP configuration information. Answer C is incorrect because the /renew6 option renews IPv6 IP addresses. Answer D is incorrect because the /release_and_renew option does not exist. Answer E is incor- rect because the /registerdns option is how to get the computer to register itself with the DNS server.

2. Answer E is correct. The command to flush local cached DNS information is ipconfig /flushdns . Answer A is incorrect because the ipconfig com- mand without any options only displays basic IP configuration information. Answer B is incorrect because the /renew option renews the IPv4 IP address- es. Answer C is incorrect because the /renew6 option renews IPv6 IP address- es. Answer D is incorrect because the /registerdns option is how to get the computer to register itself with the DNS server.

3. Answer C is correct. The two commands that show network connectivity to another computer are the ping command the tracert command. Answer A is incorrect because the ipconfig command without any options only displays basic IP configuration information. Answer B is incorrect because the arp com- mand is used to view and manage IP address to MAC address mappings. The traceroute command is found on UNIX and Linux machines. Windows machines use tracert.

4. Answer B is correct. To show all IP configuration information, you must use the ipconfig /all command. Answer A is incorrect because the ipconfig command without any options only displays basic IP configuration information. Answer C is incorrect because the arp command is used to view and manage IP address. Answers D and E are incorrect because ping and tracert are commands used to test network connectivity.

5. Answer A is correct. By looking at the example, the address assigned to the computer is 169.254.3.103, which is an Automatic Private IP address. Automatic Private IP addresses begin with 169.254. Automatic Private IP addresses are assigned to Windows computers when they cannot find a DHCP server from which to get an address. Answer B is incorrect because although a gateway address might be needed to communicate with computers on another network, the gateway was not assigned because it could not find a DHCP server. Answer

Review Question Answers

C is incorrect because this subnet mask was assigned when it could not find a DHCP server. Answer D is incorrect because you can determine the problem from the information provided in the example.

6. Answer D is correct. If you have a name resolution issue, the problem has to be with a DNS or WINS server or you have incorrect entries in your HOSTS or LMHOSTS files. Answer A is incorrect because if you can ping it by address, you have network connectivity to the server. So, it does not matter if the server is on the same subnet or a different subnet. Answer B is incorrect because you cannot block access to a computer by name but keep access by address. Answer C is incorrect because if the DHCP client service was not on, you would not be able to get any address from a DHCP server and are not able to connect to other hosts on the network.

7. Answer D is correct. If you want an address to be available from the Internet and be the same address for both IPv4 and IPv6, it must have a global unicast address that can be seen on the Internet. Answer A is incorrect because private addresses cannot be used on the public network such as the Internet. Answer B is incorrect because it has to be a single address assigned to a single computer, and not a multicast, which is used to broadcast to multiple addresses at the same time. Answer C is incorrect because a local address cannot be seen on the outside.

8. Answer D is correct. Because this person is traveling between two sites, the user needs to have a local address on each site. Therefore, you should let the local DHCP server hand out the addresses when she connects to each network. Answer A is incorrect because she can connect to one network. Therefore, the driver is working fine. Answer B is incorrect because this means that you are putting this computer directly on the Internet. Answer C is incorrect because running a troubleshooting wizard could be a lengthy process when the solution is simple.

9. Answer B is correct. To force the ping command to test a IPv6 connection, you need to use the -6 option. Answer A is incorrect because the –s option is used to specify a source address, which can come in handy when you have a com- puter with multiple network cards. Answer C is incorrect because the –a option is used to resolve the address to a host name. Answer D is incorrect because the –t option pings the specified host until it is stopped.

10. Answer C is correct. Link-local addresses are used by hosts when communicat- ing with neighboring hosts on the same link. Answer A is incorrect because a global unicast address is an address that is equivalent to IPv4 public addresses so they are globally routable and reachable on the IPv6 portion of the Internet. Answer B is incorrect because a unique local unicast address is an IPv6 address that is equivalent to IPv4 private address spaces. Answer D is incorrect because the anycast address is an IPv6 unicast address that is assigned to multiple com- puters. When IPv6 addresses communication to an anycast address, only the closest host responds.

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CHAPTER 6