Exam Objectives Frequently Asked Questions

The following Frequently Asked Questions, answered by the authors of this book, are designed to both measure your understanding of the Exam Objectives presented in this chapter, and to assist you with real-life implementation of these concepts. You will also gain access to thousands of other FAQs at ITFAQnet.com.

1.	Will I need to learn how to subnet networks as a LAN administrator?
2.	Is it necessary to memorize all the options for Netsh to manage my network effectively?
3.	Is everything I need to know about TCP/IP to do my job in this chapter?
4.	Do I need to know all the port numbers for the different protocols to manage my network?
5.	Can I use IPv6 exclusively on my network?
6.	Can I use CIDR notation on any router?
7.	Do I need a public class IP address block for my network if I have 200 hosts that need Internet access?

Answers

1.	Yes, the ability to design and implement and support networks using TCP/IP depends on your ability to understand IP addressing practices. It is also important to understand subnetting for troubleshooting problems and expanding your network.
2.	You should be familiar with the various functions provided by Netsh and understand its importance in configuring IPv6 and other networking components. You may find useful functionality that can simplify repetitive tasks, since netsh is a command-line tool and provides you with a means to automate tasks. You can even use it to back up configurations for services such as DHCP and DNS to simplify building similar machines on your network.
3.	No, volumes of data exist on TCP/IP, including many valuable Internet resources such as IPv6.org and IETF.org. Every day, new information about the development of TCP/IP protocols is available. In addition, there are books dedicated solely to TCP/IP and still others that talk about security on networks that use TCP/IP.
4.	You should be familiar with the common port numbers, such as those for FTP, HTTP, and SMTP, but it is not necessary to memorize every single one. Understanding how to determine which port does what can help you identify which services are in use on machine, as well as provide better security for your network. You can learn to use and identify different ports to do other tasks, such as testing SMTP on port 25 using telnet.exe (the Telnet port defaults to 22).
5.	Yes, however, due to the limited application support, it would be very difficult at this point to eliminate IPv4 and still function efficiently. For instance, there is no IPv6 implementation of DHCPv6, so it is difficult to manage configuration settings for networks that have many clients. Other common protocols such as SMTP, POP, and NNTP do not currently support IPv6. In addition, the majority of Internet resources are using IPv4, and you would require some implementation of IPv4 on your network to access those resources.
6.	No, only certain versions of the routing protocols RIPv2 and OSPF support CIDR notation. Routers using RIPv1 do not support CIDR notation, and thus require the full routing information to be provided. This could present issues if you are using CIDR notation for routers that will interface with RIPv1 routers and router discovery. Most hardware routers can use CIDR notation to define routes. CIDR notation can help reduce the number of route entries that must be added to the routing table.
7.	No, it would be very costly and difficult to obtain an entire block of class C addresses. You should implement a firewall. Then you will be provided with either a single IP address or a small subnet of six or fewer public addresses that will provide the external interface to the world. Intead, y\ou should use a private IP addressing scheme internally to allow for outbound traffic to the Internet via NAT. Public addresses would be necessary for Web servers, VPN over the Internet, and other interfaces that need to be accessible over the Internet. E-mail servers must have a public IP address to allow delivery of Internet messages. You may be hosting a DNS server that provides host name resolution for your public Web servers. The DNS server would require a public interface to allow other clients to perform lookups, to update and receive updates for a zone, and so on.