unit iii – network layer · 2018-05-08 · trk / ap / ece / vvcet / ec2352 – cn / unit 3 unit...

TRK / AP / ECE / VVCET / EC2352 – CN / UNIT 3

UNIT III – NETWORK LAYER

LOGICAL ADDRESSING:

IP Address – to mean logical address in the network layer of the TCP/IP protocol suite. 32 bit address – gives maximum of 232 addresses. IPv4 and IPv6

IPv4 ADDRESSES

32 bit address Unique and Universal

Address Space

Total number of addresses used by the protocol The address space of IPv4 is 232 or 4294967296

Notations

Binary notation 01110101 10010101 00011101 00000010 Dotted decimal notation 117.149.29.2

Classful Addressing:

Classes and Blocks Netid and Hostid Mask Subnettingsupernetting Address depletion

Classless Addressing:

1.Address Blocks 2.Mask 3.Network Address 4.Hierarchy – twolevel Hierarchy (No Subnetting), Three Levels of Hierarchy (Subnetting)

5.More levels of Herarachy 6.Address Allocation


Network Address Translation (NAT):

IPv6:

128 bits long

Hexadecimal colon Notation:

Abbrevation:

Address Space:

Unicast Addresses

MulticastAddresses


ReservedAddress

LocalAddress

INTERNET PROTOCOL:

INTERNETWORKING:


Internet as a Datagram Network: switching at the network layer in the internet uses the datagram approach to packet

switching


Internet as a connectionless Network:

Communication at the network layer in the internet is connectionless.

IPv4:

Datagram:

Fragmentation:

Maximum Transfer Unit:

Identification:

Flags:

Fragmentation Offset:


IPv6:

Known as IPng (Internetworking Protocol, Next Generation)

Advantages:

Larger Address Space Better Header Format New Options Allowance for extension Support for resource allocation Support for more security

Packet Format:

Base Header


Extension Headers:

Transition from IPv4 to IPv6:

Dual Stack:


Tunneling:

Header Translation:

ADDRESS MAPPING:

Mapping Logical to Physical Address: ARP:


Encapsulation:

Proxy ARP:

MAPPING PHYSICAL TO LOGICAL ADDRESS:RARP,BOOTP, and DHCP:

RARP: Reverse Address Resolution Protocol – used to find logical address for amachine that knows only its physical address.

BOOTP: Bootstrap Protocol – its a client/server protocol designed to provide physicaladdress to logical address mapping.

DHCP: Dynamic Host configuration Protocol – it provides static and dynamic addressallocation that can be manual or automatic.

Static Address Allocation Dynamic Address Allocation Manual and Automatic Configuration.


ICMP: internet control message protocol

A host sometimes needs to determine if a router or another host is alive andsometimes a network administrator needs information from another host or router.

Types of messages:

Error reporting messages Query messages

Message Format:

Error Reporting:

Query:

Debugging Tools:

Ping Traceroute


IGMP: Internet Group Management Protocol

Used in multicasting

Group Management:

It helps a multicast router create and update a list of loyal members related toeach router interface.

IGMP Messages:

Message Format:

IGMP Operation:

Joining a Group Leaving a group Monitoring Membership

Encapsulation:


DELIVERY:

Direct DeliveryThe destination of the packet is a host connected to the same network as thedeliverer.

Indirect DeliveryThe packet goes from router to router until it reaches the one connected tothe same physical network as its final destination.

FORWARDING:Forwarding Techniques:

Next Hop Method Versus Route Method Network Specific Method Versus Host Specific Method Default Method


Forwarding Process:

Routing Table:Static Routing Table Dynamic Routing Table


UNICAST ROUTING PROTOCOLS:Static table: manual updatesDynamic Table: automatic updateOptimization:

When a router receives a packet, to which network should it pass thepacket, the decision is based on Optimization.

Intra and Interdomain Routing:

AS – Autonomous System - group of networks and routers under the authority ofsingle administration.

Intra domain routing – routing inside an autonomous system

Interdomain routing – routing between AS

RIP – Routing Information Protocol – implementation of Distance Vector protocol

OSPF – open Shortest path first – Implementation of link state protocol

BGP – Border Gateway Protocol - Implementation of Path vector protocol

Distance Vector Routing:

Initialization

Sharing

Updating

Periodic Update

Triggered Update


RIP:

Link State Routing:

OSPF:

Path Vector Routing:

BGP:


MULTICAST ROUTING PROTOCOLS:

Unicasting:

Multicasting:

in unicasting, therouter forwards the receivedpacket through only one of itsinterfaces.

In multicasting, therouter may forward the receivedpacket through several of itsinterfaces.

Broadcasting

Shortest path trees

Source based tree

Group Shared tree

Routing Protocols:

Multicast LinkState Routing

Multicast open shortest path first Multicast Distance vector Multicast Distance vector routing Distance vector multicast routing protocol

CBT:

PIM: PIM-DM, PIM-SM

MBONE:

unit iii – network layer · 2018-05-08 · trk / ap / ece / vvcet / ec2352 – cn / unit 3 unit...

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