Introduction to Networking Concepts

Mahmmoud Mahdi

Introductory

Understanding TCP/IP Addressing The Domain Name System (DNS) The Dynamic Host Configuration Protocol

(DHCP) The Routing & Remote Access (RRAS)

service The Network Access Protection (NAP)

service

Understanding TCP/IP Addressing

Network Protocols

Provide the logical "language" for communication

Two computers must be configured with the same network protocols in order to communicate and transfer information.

Transmission Control Protocol/Internet Protocol (TCP/IP)

The most common networking protocol

Consists of a suite of different protocols that work in concert to allow computers to communicate on a TCP/IP network.

By subdividing TCP/IP networks into smaller groupings called subnets.

Addressing

In order for any computer or host, a computer, printer, or other device configured with a network interface, to communicate on a TCP/IP network, it must be configured with a valid IP address.

IP address: Is a software address, not a hardware address Used for finding hosts on a local network. Allow hosts on one network to communicate with

a host on a different network.

TCP/IP Basics

192.168.2.1 192.168.2.3

192.168.2.2

192.168.2.4

192.168.2.5

IP address

Each IP address consists of two components: Network Address:▪ This portion of the IP address is shared by all TCP/IP

hosts on a particular network or subnet. Host Address:▪ This comprises the portion of me IP address that is

unique to a particular computer or host. IP address = the network address + the host

address must be unique across an entire TCP/IP network.

IP address

In addition to the IP address, each TCP/IP host must be configured with the following: Subnet Mask▪ Used to identify which network the TCP/IP host

resides on by defining where the network address stops and the host address begins.

Default Gateway▪ Allows a host to communicate with devices that reside

on a remote network or location.

IP version 4 (IPv4)

The first implementation of the Internet Protocol (IP)

It uses 32 bits (4 bytes, or octets) for addressing. providing a limit of 232 possible addresses

Represented using dotted-decimal notation the decimal value of each byte is shown using

periods to separate the bytes for example:

192.1.120.84 or 192.5.18.102

IPv4 Address

1 1 0 0 0 0 0 0 1 0 1 0 1 0 0 0 0 0 0 0 0 0 1 0 0 0 0 0 0 0 0 1

12

48

1632

64128 128+64=192

192.168.2.1

IP Terminology

Network address: Uniquely identifies each network. Every host on the same network share that

network address as a part of its IP address Used in routing to send packets to a remote

network▪ Ex: 10.0.0.0, 172.16.0.0, 192.168.10.0

Host address: Uniquely identifies each host on a network

IP Terminology

Broadcast address: Used by application and hosts to send

information to all nodes on a network. Ex: 255.255.255.255 ▪ all networks, all hosts

Ex: 172.16.255.255 ▪ all subnets and hosts on a network 172.16.0.0

Classes of Network

Classful Addressing The field for the network number was a

different length for different classes of network, and the remaining bits were used for the host number.

Summary of the three classes of networks

Network Host Host Host

Network Network Host Host

Network Network Network Host

Class A:

Class B:

Class C:

Class E:

Class D:

8 bits 8 bits 8 bits 8 bits

Multicast

Research

Classes of Network

Network Class

Leading Bits

Bits for Network Number

Number of Networks

Bits for Host Number

Maximum Hosts

Class A 0 7 126 24 16,777,214

Class B 10 14 16,384 16 65,534

Class C 110 21 2,097,152 8 254

Class D (multicast)

1110

Class E(reserved)

1111

Network Address Range

Class A 00000000 = 0 01111111 = 127

Class B 10000000 = 128 10111111 = 191

Class C 11000000 = 192 11011111 = 223

Class D 11100000 = 224 11101111 = 239

Class E 11110000 = 240 11111111 = 255

Network Classes Address Range

Network Class Starting Address

Ending Address Bitmask

Class A 0.0.0.0 127.255.255.255 255.0.0.0

Class B 128.0.0.0 191.255.255.255 255.255.0.0

Class C 192.0.0.0 223.255.255.255 255.255.255.0

Class D (multicast) 224.0.0.0 239.255.255.251

Class E (reserved) 240.0.0.0 255.255.255.255

Reserved IP Address

Address FunctionNetwork address of all 0’s Mean this network

Network address of all 1’s Mean all networks

Network 127.0.0.1 Reserved for loopback tests

Host address of all 0’s Mean network address

Host address of all 1’s Mean all hosts

Entire IP address set to all 0’s The default route, Any network

Entire IP address set to all 1’s Broadcast to all hosts on the current network

IPv4 Address Blocks

Two Types of IP Addresses Public▪ Obtained from ISP▪ One for every computer directly connected to the Internet▪ Block – A group of IP addresses sharing a single network ID

The addresses included within the address block

Private▪ Freely assigned in private network

Private IP Addresses

Can be used on private network Not routable through the internet Creating a measure of well-needed security Saves valuable IP address space Network Address Translation (NAT)

Takes a private IP address and convert it for use on the internet.

Reserved Private IP Address Space

Address Class Address RangeClass A 10.0.0.0 - 10.255.255.255

Class B 172.16.0.0 - 172.31.255.255

Class C 192.168.0.0 - 192.168.255.255

APIPA

Self-assigned private IP address Allows computers to communicate without

requiring DHCP or manual IP configuration.

Automatic Private IP Addressing (APIPA)169.254.0.0 - 169.254.255.255

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