Chapter 6. Working with TCP/IP

OBJECTIVES

This chapter covers the following CompTIA-specified objectives for the “Protocols and Standards” section of the Network+ exam.

Define the purpose, function, and/or use of the following protocols within TCP/IP: IP, TCP, UDP, FTP, TFTP, SMTP, HTTP, HTTPS, POP/IMAP, Telnet, ICMP, ARP, and NTP.

• The TCP/IP protocol suite is composed of many different protocols. As a network administrator, you need to be able to identify the various protocols and their purposes.

Define the function of TCP/UDP ports and identify well-known ports.

• Understanding the function and role of ports in TCP/IP networking is a key skill for a network administrator.

Identify the purpose of the following network services: DHCP/BOOTP, DNS, NAT/ICS, WINS, SNMP.

• Many different TCP/IP-related services are used on networks. Understanding the services available and their functions is a key skill in network administration.

Identify IP addresses (IPv4, IPv6) and their default subnet masks.

• IP addressing is perhaps one of the most complex principles in TCP/IP networking. This chapter introduces you to TCP/IP addressing as it relates to real-world networking scenarios.

Identify the purpose of subnetting and default gateways.

• Subnetting and default gateways are important elements of TCP/IP networking.

Identify the differences between public and private networks.

• Private network address ranges are now commonly used as a means to provide flexible TCP/IP addressing schemes within organizations. You are very likely to encounter private network addressing in the real world.

OUTLINE

Introduction

TCP/IP Protocols

Internet Protocol (IP)

Transmission Control Protocol (TCP)

How TCP Works

User Datagram Protocol (UDP)

File Transfer Protocol (FTP)

Trivial File Transfer Protocol (TFTP)

Simple Mail Transfer Protocol (SMTP)

Hypertext Transfer Protocol (HTTP)

Hypertext Transfer Protocol Secure (HTTPS)

Post Office Protocol/Internet Message Access Protocol (POP/IMAP)

Telnet

Internet Control Message Protocol (ICMP)

Address Resolution Protocol (ARP)

Network Time Protocol (NTP)

TCP/IP Protocol Suite Summary

TCP/UDP Ports

TCP/IP-Based Network Services

Dynamic Host Configuration Protocol (DHCP)

The DHCP Process

Fault-Tolerant DHCP Configurations

Should You Use DHCP?

BOOT Protocol (BOOTP)

Domain Name System (DNS)

The DNS Namespace

Types of DNS Entries

DNS in a Practical Implementation

Network Address Translation (NAT) and Internet Connection Sharing (ICS)

NAT

How NAT Works

ICS

Simple Network Management Protocol (SNMP)

Components of SNMP

SNMP Management Systems

SNMP Agents

Management Information Bases (MIBs)

SNMP Communities

Windows Internet Name Service (WINS)

WINS in the Real World

TCP/IP Service Summary

IP Addressing2

General IP Addressing Principles

IPv4

IP Address Classes

Subnet Mask Assignment

Broadcast Addresses and “This Network”

Classless Interdomain Routing (CIDR)

IPv6

IPv6 Addressing

Other Benefits of IPv6

Subnetting

Reasons to Subnet

Default Gateways

Identifying the Differences Between Public and Private Networks

Private Address Ranges

Practical Uses of Public and Private IP Addressing

Chapter Summary

Apply Your Knowledge

STUDY STRATEGIES

• Read the objectives at the beginning of the chapter.

• Study the information in the chapter, paying special attention to the tables, which summarize key information.

• Review the objectives again.

• Answer the exam questions at the end of the chapter and check your results.

• Use the ExamGear test on the CD-ROM that accompanies this book to answer additional exam questions concerning this material.

• Review the notes, tips, and exam tips in this chapter. Make sure you understand the information in the exam tips. If you don't understand the topic referenced in an exam tip, refer to the information in the chapter text and then read the exam tip again.