Netwrork

Computer Networks
Contents
Contents 1
Question No. 1 (6 Marks) 2
Introduction to LAN 2
Introduction to WAN 2
Question No. 2 (6 Marks) 2
OSI Layer 2
TCP/ IP 4
Question No. 3 (6 Marks) 8
Link Layer 8
Ethernet & 802.3 9
SLIP 10
PPP 12
Question No. 4 (7 Marks) 12
IP 14
General 14
IPv4 Address 15
IP Packet structure 16
References : 16
ICMP 16
ARP 19
RARP 19
UDP – User Datagram Protocol 20
Telnet Protocol 39
FTP – File Transfer Protocol 41
III – Unit Test topics 44
What is a firewall? Explain 2 types of firewall. 44

Question No. 1 (6 Marks)

Introduction to LAN

  1. Three LAN implementations are used most commonly
      a. Ethernet/IEEE 802.3,
      b.   Token Ring/IEEE 802.5, and
      c. Fiber Distributed Data Interface (FDDI)

Router - A node that sends network packets in one of many possible directions to get them to their destination. It can also take decision in which route the information should take. It operates at network layer.

Gateways
It is a generic term that refers to an entity used to interconnect two or more networks that have different rules of communication.
Introduction to WAN

Question No. 2 (6 Marks)

OSI Layer

  1. (Open Systems Interconnection) model defined by the International Organization for Standardization.
  2. The OSI reference model is a conceptual model composed of seven layers, each specifying particular network functions. The model was developed by the International Organization for Standardization (ISO) in 1984, and it is now considered the primary architectural model for inter-computer communications.
  3. The basic idea of a layered architecture is to divide the design into small pieces. Each layer adds to the services provided by the lower layers in such a manner that the highest layer is provided a full set of services to manage communications and run the applications.
  4. The benefits of the layered models are
      a. Modularity and...