Networks fundamentals

by assistant lecturer

Fuad Ali3/26/2013

FUAD ALI

Types of Networks (geographically)

1. LAN - Local Area Network2. WLAN - Wireless Local Area Network3. WAN - Wide Area Network4. MAN - Metropolitan Area Network5. SAN - Storage Area Network, System Area Network, Server Area Network, or sometimes Small Area Network6. CAN - Campus Area Network, Controller Area Network, or sometimes Cluster Area Network7. PAN - Personal Area Network8. DAN - Desk Area Network

FUAD ALI

The DifferencesBetweenLAN & WAN

Types of Networks (no. of hosts)

Computer Identifiers

1.Computer Name : 256 characters (unique inside only , non-standard)2.Host Name : 256 characters (always unique , standard)3.IP Address : 4 bytes (always unique , standard)4.MAC Address : 6 bytes (always unique , standard)

MAC : B.C. FF FF FF FF FF FF IP : B.C. all host potion bits converted to 1s or 255 in decimal

Port No. : 0 – 1023 reserved for applications

Physical Addressing = MAC in layer 2

Logical Addressing = IP in layer 3

Identify service = Port No. in layer 4

Types of Addressing

Types of IPs

abbreviated Invisible Ranges (non routed addresses) Class

10.0.0.0 / 8 10.0.0.1 – 10.255.255.254 16000000 A

172.16.0.0 / 12 172.16.0.1 – 172.31.255.254 10000000 B

192.168.0.0 / 16 192.168.0.1 – 192.168.255.254 65000 C

1. Private IP Addresses

2. Private IP Addresses

3. 127.x.x.x !!?

4. 0.0.0.0 !!?

IP Address & subnet maskClass Mask High bits IP ranges

A 255.0.0.0 = /8 0 1.0.0.1 – 126.255.255.254

B 255.255.0.0 =/16 10 128.0.0.1 – 191.255.255.254

C 255.255.255.0 =/24 110 192.0.0.1 – 223.255.255.254

Why subnet mask ?

Characteristic IPv4 IPv6

Format

x.x.x.x

4, 8-bit fields

Separated by dots

x:x:x:x:x:x:x:x

8, 16-bit fields

Separated by colons

Field Representation Decimal FormatGroups of 4 hexadecimal digits, case sensitive forA, B, C, D, E and F.

Leading Zeroes Omitted Optional

Successive Zero Fields Must be included Can be represented by “::” once

in an address.

IPv6 Addressing

IPv6 Addressing• IPv6 Representation • Any single, contiguous string of one or more 16-

bit segments consisting of all zeroes can be represented once with a double colon.

1080:0:0:0:8:800:200C:417A = 1080::8:800:200C:417A

FF01:0:0:0:0:0:0:101 = FF01::101

0:0:0:0:0:0:0:1 = ::1

0:0:0:0:0:0:0:0 = ::

IPv6 Addressing

• IPv6 Representation:– Prefix:• IPv4 prefix (the network portion of the address) can be

dotted decimal or bit count.• e.g. 198.10.0.0 255.255.255.0 or /16

• IPv6 prefix is always represented by bit count.– e.g. 3ef8:ca62:12:cc::2/64 16 32 48 64

UTP (Unshielded Twisted Pair) & STP( Shielded Twisted Pair)

Twisting provide :

1- protection against crosstalk, noise generated by adjacent pairs .

2- cancellation of the magnetic field EMI.

Straight UTP Cable

Side1 : WO O WG B WB G WBr Br T568B

Side2 : WO O WG B WB G WBr Br T568B

Cross-Over UTP CableSide1 : WO O WG B WB G WBr Br T568B

Side2 : WG G WO B WB O WBr Br T568A

Roll-Over UTP CableSide1 : WO O WG B WB G WBr Br T568B

Side2 : Br Br G WB B G O WO

LLC & MAC

Theoretically model

Implem

ented model

IPv6 vs IPv4 16 Bytes → 3.4 x 10 38 IP Addresses 4 Bytes → 4.3 x 10 9 IP Addresses