- Data Comm & Networks Home
- DCN - Overview
- DCN - What is Computer Network
- DCN - Uses of Computer Network
- DCN - Computer Network Types
- DCN - Network LAN Technologies
- DCN - Computer Network Models
- DCN - Computer Network Security
- DCN - Components
- DCN - Connectors
- DCN - Switches
- DCN - Repeaters
- DCN - Gateways
- DCN - Bridges
- DCN - Socket
- DCN - Network Interface Card
- DCN - NIC: Pros and Cons
- DCN - Network Hardware
- DCN - Network Port
- Computer Network Topologies
- DCN - Computer Network Topologies
- DCN - Point-to-point Topology
- DCN - Bus Topology
- DCN - Star Topology
- DCN - Ring Topology
- DCN - Mesh Topology
- DCN - Tree Topology
- DCN - Hybrid Topology
- Physical Layer
- DCN - Physical Layer Introduction
- DCN - Digital Transmission
- DCN - Analog Transmission
- DCN - Transmission media
- DCN - Wireless Transmission
- DCN - Transmission Impairments
- DCN - Multiplexing
- DCN - Network Switching
- Data Link Layer
- DCN - Data Link Layer Introduction
- DCN - Data Link Control & Protocols
- DCN - RMON
- DCN - Token Ring Network
- DCN - Hamming Code
- DCN - Byte Stuffing
- DCN - Channel Allocation
- DCN - MAC Address
- DCN - Cyclic Redundancy Checks
- DCN - Error Control
- DCN - Flow Control
- DCN - Framing
- DCN - Error Detection & Correction
- DCN - Error Correcting Codes
- DCN - Parity Bits
- Network Layer
- DCN - Network Layer Introduction
- DCN - Network Addressing
- DCN - Routing
- DCN - Internetworking
- DCN - Network Layer Protocols
- DCN - Routing Information Protocol
- DCN - Border Gateway Protocol
- DCN - OSPF Protocol
- DCN - Network Address Translation
- DCN - Network Address Translation Types
- Transport Layer
- DCN - Transport Layer Introduction
- DCN - Transmission Control Protocol
- DCN - User Datagram Protocol
- DCN - Congestion Control
- DCN - TCP Service Model
- DCN - TLS Handshake
- DCN - TCP Vs. UDP
- Application Layer
- DCN - Application Layer Introduction
- DCN - Client-Server Model
- DCN - Application Protocols
- DCN - Network Services
- DCN - Virtual Private Network
- DCN - Load Shedding
- DCN - Optimality Principle
- DCN - Service Primitives
- DCN - Services of Network Security
- DCN - Hypertext Transfer Protocol
- DCN - File Transfer Protocol
- DCN - Secure Socket Layer
- Network Protocols
- DCN - ALOHA Protocol
- DCN - Pure ALOHA Protocol
- DCN - Sliding Window Protocol
- DCN - Stop and Wait Protocol
- DCN - Link State Routing
- DCN - Link State Routing Protocol
- Network Algorithms
- DCN - Shortest Path Algorithm
- DCN - Routing Algorithm
- DCN - Leaky Bucket Algorithm
- Wireless Networks
- DCN - Wireless Networks
- DCN - Wireless LANs
- DCN - Wireless LAN & IEEE 802.11
- DCN - IEEE 802.11 Wireless LAN Standards
- DCN - IEEE 802.11 Networks
- Multiplexing
- DCN - Multiplexing & Its Types
- DCN - Time Division Multiplexing
- DCN - Synchronous TDM
- DCN - Asynchronous TDM
- DCN - Synchronous Vs. Asynchronous TDM
- DCN - Frequency Division Multiplexing
- DCN - TDM Vs. FDM
- DCN - Code Division Multiplexing
- DCN - Wavelength Division Multiplexing
- Miscellaneous
- DCN - Shortest Path Routing
- DCN - B-ISDN Reference Model
- DCN - Design Issues For Layers
- DCN - Selective-repeat ARQ
- DCN - Flooding
- DCN - E-Mail Format
- DCN - Cryptography
- DCN - Unicast, Broadcast, & Multicast
- DCN - Network Virtualization
- DCN - Flow Vs. Congestion Control
- DCN - Asynchronous Transfer Mode
- DCN - ATM Networks
- DCN - Synchronous Vs. Asynchronous Transmission
- DCN - Network Attacks
- DCN - WiMax
- DCN - Buffering
- DCN - Authentication
- DCN Useful Resources
- DCN - Quick Guide
- DCN - Useful Resources
Network Addressing
Layer 3 network addressing is one of the major tasks of Network Layer. Network Addresses are always logical i.e. these are software based addresses which can be changed by appropriate configurations.
A network address always points to host / node / server or it can represent a whole network. Network address is always configured on network interface card and is generally mapped by system with the MAC address (hardware address or layer-2 address) of the machine for Layer-2 communication.
There are different kinds of network addresses in existence:
IP
IPX
AppleTalk
We are discussing IP here as it is the only one we use in practice these days.
IP addressing provides mechanism to differentiate between hosts and network. Because IP addresses are assigned in hierarchical manner, a host always resides under a specific network.The host which needs to communicate outside its subnet, needs to know destination network address, where the packet/data is to be sent.
Hosts in different subnet need a mechanism to locate each other. This task can be done by DNS. DNS is a server which provides Layer-3 address of remote host mapped with its domain name or FQDN. When a host acquires the Layer-3 Address (IP Address) of the remote host, it forwards all its packet to its gateway. A gateway is a router equipped with all the information which leads to route packets to the destination host.
Routers take help of routing tables, which has the following information:
Method to reach the network
Routers upon receiving a forwarding request, forwards packet to its next hop (adjacent router) towards the destination.
The next router on the path follows the same thing and eventually the data packet reaches its destination.
Network address can be of one of the following:
Unicast (destined to one host)
Multicast (destined to group)
Broadcast (destined to all)
Anycast (destined to nearest one)
A router never forwards broadcast traffic by default. Multicast traffic uses special treatment as it is most a video stream or audio with highest priority. Anycast is just similar to unicast, except that the packets are delivered to the nearest destination when multiple destinations are available.