Q&A for May 18, 2001

Welcome to Certifiable, your exam prep headquarters. Here you'll find questions about some of the tricky areas that are fair game for the certification exams. Following the questions, you'll find the correct answers and explanatory text. We change the questions weekly.

Questions (May 18, 2001)
Answers (May 18, 2001)

Although scarce on the Windows NT exams, TCP/IP questions permeate all the Windows 2000 exams. Sometimes you find a few simple questions; other times, the correct answer depends on a piece of information about network connectivity. If you look at the exams' skills lists, you'll find they all expect a broad understanding of networks. For Win2K, that means TCP/IP and all of its related services.

For example, Exam 70-221, Designing a Microsoft Windows 2000 Network Infrastructure, is almost a direct replacement for the retired NT 4.0 TCP/IP exam (70-059). The upcoming Exam 70-226, Designing Highly Available Web Solutions with Microsoft Windows 2000 Server Technologies, will need to test TCP/IP heavily because if TCP/IP services fail, the Web server fails. Finally, Exam 70-219, Designing a Microsoft Windows 2000 Directory Services Infrastructure, must cover DNS, DHCP, and WINS because Active Directory (AD) domains depend on DNS for name resolution for everything from clients finding a server to domain controllers (DCs) finding each other. If DNS fails, your domain fails.

My next few columns will test your knowledge of TCP/IP. We'll start with some simple questions and work our way up in difficulty to some questions similar to those you'll find on the second set of core exams (i.e., the set from which you can pick your fifth core exam). Knowing TCP/IP can mean the difference between passing and failing an exam; use these questions to see whether you're ready.

Questions (May 18, 2001)

Question 1
While setting your Windows 2000 Professional machine's TCP/IP configuration parameters, you view the following TCP/IP properties:

IP Address: 192.123.0.25Subnet Mask: 255.255.255.0Default Gateway: 192.123.2.1Preferred DNS Server: 192.123.0.10Alternate DNS Server: 192.123.2.26

Which of the following statements are true? (Choose all that apply.)

Question 2
You're the network administrator for BFQ Architects, which has a star-bus hybrid networking topology installed. Company employees require Internet access to conduct research about their clients' companies. To support all 2000 employees, the previous network administrator configured the routing environment as follows:

Employees whose machines are connected to segment 192.26.33.0/24 can't access the Internet. Employees whose machines are connected to segments 192.45.27.0/24 and 192.33.101.0/24 can connect to the Internet. Employees on segment 192.26.33.0/24 can communicate with hosts on segments 192.45.27.0/24 and 192.33.101.0/24. Employees on segments 192.45.27.0/24 and 192.33.101.0/24 can communicate with hosts on 192.26.33.0/24; however, hosts on segment 6.0.0.0/24 can't.

Why can't employees on segment 192.26.33.0/24 connect to the Internet?

Question 3
Mary, a senior consultant, has been assigned to help plan the TCP/IP networking scheme for ABC Company. Currently, ABC has 20 branch offices, each with two network segments per branch. Each branch is connected to the ABC corporate office in Chicago to facilitate data replication between the local branch client databases and the master client database. The ABC corporate office currently has an IT network segment, a Research and Development network segment, a Sales and Marketing network segment, and a Finance network segment.

The largest of these segments supports 450 users. ABC Company is forecasting tremendous growth over the next 5 years. It expects that the current network segment count will grow to 77 networks and that the largest network segments will support 1000 hosts.

ABC's goal is to use one base network number to create the correct number of IP network addresses to associate to each network segment. ABC has charged Mary with completing this task, and she has secured an IP network address of 132.64.0.0/16 from an ISP.

Based on this address, which IP network number(s) below will support both the future number of network segments and the growth in the number of hosts per segment?

Answers (May 18, 2001)

Answer to Question 1
The correct answers are A—This TCP/IP client will be able to communicate with the primary DNS server for host name resolution; and D—This TCP/IP client will be able to communicate with all TCP/IP hosts on the same TCP/IP network.

The client won't be able to use its configured default gateway (answer B) because the identified IP address is for a different IP network segment. This fact also prevents the client from using the alternate DNS server for name resolution (answer C).

Answer to Question 2
The correct answer is C—The network configuration uses a default gateway routing solution. The default gateway solution, where the router doesn't have any routing table entries other than the immediate networks to which it is configured, allows for only a maximum hop of two networks from the source network.

Answer to Question 3
The correct answer is E—No answer is correct. In this case, no way exists to subdivide the 132.64.0.0 network range to meet ABC's criteria of 77 networks and 1000 hosts.

Answers A and B can support the largest number of network IDs; however, the number of hosts supported for each network is less than the future growth target of 1000 hosts maximum on a network segment. Answers C and D can support the largest number of IP hosts per segment; however, the number of networks that can be created with a custom subnet mask doesn't meet the growth of networks within the 5-year period.