IS3120 Network Communications Infrastructure
This presentation is the property of its rightful owner.
Sponsored Links
1 / 36

IS3120 Network Communications Infrastructure Unit 9 PowerPoint PPT Presentation


  • 297 Views
  • Uploaded on
  • Presentation posted in: General

IS3120 Network Communications Infrastructure Unit 9 Link-State IP Routing, Campus Backbones, WANs, and Classless Inter-Domain Routing (CIDR ). Learning Objective. Formulate and plan the implementation of link-state routing protocols to meet business requirements. Key Concepts.

Download Presentation

IS3120 Network Communications Infrastructure Unit 9

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript


Is3120 network communications infrastructure unit 9

IS3120 Network Communications Infrastructure

Unit 9

Link-State IP Routing, Campus Backbones, WANs, and Classless Inter-Domain Routing (CIDR)


Learning objective

Learning Objective

  • Formulate and plan the implementation of link-state routing protocols to meet business requirements.


Key concepts

Key Concepts

  • Classless Inter-Domain IP Routing (CIDR)

  • Link-state routing protocols

  • OSPF v2

  • OSPF two-tier hierarchical IP backbone network design for an enterprise WAN

  • OSPF, Variable Length Subnet Masking (VLSM) configuration


Explore concepts

EXPLORE: CONCEPTS


Classless inter domain ip routing cidr review

Classless Inter-Domain IP Routing (CIDR) Review

  • Referred to as “supernetting”

  • An alternative to traditional IP subnetting

  • Assigns IP addresses without using Class A, Class B, or Class C

  • IP address represented as A.B.C.D /n, where "/n" is the number of bits in the mask


Ipv4 cidr block syntax

IPv4: CIDR Block Syntax

  • CIDR block: group of IP addresses sharing the same prefix

  • Prefix is determined by

    • Translating dot notation to binary

    • Identifying # of bits that are shared


Ipv4 cidr example 1

IPv4: CIDR Example #1

  • Address block 168.12.0.0/16

  • Any IP address sharing the same initial 16 bits is in the same network

  • Range is 168.12.0.0 - 168.12.255.255


Ipv4 cidr example 2

IPv4: CIDR Example #2

  • Address Block 168.12.176.0/20

  • Any IP address sharing the same initial 20 bits is in the same network

  • Range is 168.12.176.0 - 168.12.191.255


Who uses cidr and who does not

Who Uses CIDR, and Who Does Not?


Distance vector versus link state

Distance Vector versus Link State


Addressing and routing protocols

Addressing and Routing Protocols


Link state routing protocols

Link-State Routing Protocols

  • Open Shortest Path First (OSPF) for IP

  • Intermediate System to Intermediate System (IS-IS) for Connectionless Network Service and IP

  • Novell NetWare Link Services Protocol (NLSP)


Ospf and is is

OSPFand IS-IS

  • Interior gateway protocols

  • Route IP packets within an autonomous system

  • Use multicast to discover neighbor routers (Hello process)

  • Support variable-length subnet masks and route summarization


Differences between ospf and is is

Differences between OSPF and IS-IS


Ospf v3

OSPFv3

  • Based on OSPFv2, updated for IPv6

  • 128-bit addresses

  • Multiple addresses per interface

  • Can run over a link

  • Uses IPSec

  • Generalizes link-state advertisement (LSA) flooding scope

  • Removes authentication from protocol


Link state routing hello process

Link-State Routing Hello Process


Routers

Routers

  • Internal routers

  • Backbone routers

  • Area border router (ABR)

  • Autonomous system boundary router (ASBR)

  • Designated router (DR)

  • Backup designated router (BDR)


Broadcast networks

Broadcast Networks

  • DRs and BDRs

  • Only DR and BDR form full adjacencies with other routers

  • Remaining routers remain in a two-way state with each other

  • If DR or BDR missing, re-election of missing router takes place


Designated router

Designated Router

  • Adjacencies formed with DR and BDR only

  • LSAs propagate along the adjacencies

DR

BDR


Ospf equal cost multipath

OSPF Equal Cost Multipath

  • If n paths to same destination have equal cost, OSPF installs n entries in forwarding table

  • Loadsharing over npaths

  • Useful for expanding links across an ISP backbone

  • Don’t need hardware multiplexors or static routing


Other protocols vrrp and hsrp

Other Protocols - VRRP and HSRP

  • Virtual Router Redundancy Protocol (VRRP)

    • Open standard protocol

    • Provides router state information

  • Hot Standby Router Protocol (HSRP)

    • Cisco proprietary protocol

    • Does not advertise IP routes or affect routing table


Explore processes

EXPLORE: PROCESSES


Ospf and addressing design

OSPF and Addressing Design

  • Idea behind VLSMs is to offer more flexibility

  • Without VLSM, only one subnet mask applied to a network

  • This restricts the number of hosts given the number of subnets required


Ospf and vlsm

OSPF and VLSM

  • OSPF can carry multiple subnet information

  • Other protocols such as RIP and IGRP cannot


Ospf rip and vlsm

OSPF, RIP, and VLSM

OSPF

RIP

203.240

255.255.255.252

Router B

16.68

16.67

E0

E0

S1

Router A

203.240

255.255.255.192

16.1

16.2

S0

Router C


Configuring ospf for vlsm

Configuring OSPF for VLSM

  • OSPF RFC (1583) does not specify what is the best way to architect a network

  • When subnetting, the router complains if the combination IP address and mask result in a subnet 0

  • When doing protocol redistribution, it is better to avoid OSPF filtering


Design an ospf backbone network

Design an OSPF Backbone Network

  • Use variable subnet addressing for IPv4

  • Plan a two-tier hierarchical addressing scheme

  • Pick an appropriate metric

  • Designate backbone (area 0) at the center

  • Attach (physically) other areas to area 0


Design an ospf backbone network1

Design an OSPF Backbone Network

  • Use loopbacks or manually configured router IDs areas

  • Use appropriate address aggregation

  • Use stubby/totally stubby areas where possible


Explore roles

EXPLORE: ROLES


Ospf network types

OSPF Network Types

  • Broadcast multi-access

  • Point-to-point

  • Point-to-multipoint broadcast

  • Point-to-multipoint non-broadcast

  • Non-broadcast multi-access (NBMA)


Explore contexts

EXPLORE: CONTEXTS


Ospf in multi access networks

OSPF in Multi-access Networks

B

A

RIP

Internal Routers

C

BGP


Ospf in multi access networks1

OSPF in Multi-access Networks

A

B

C

G

D

F

E


Explore rationale

EXPLORE: RATIONALE


Distance vector or link state

Distance Vector or Link State?

  • When planning a network design, what considerations are made whether to choose distance vector or link-state protocols?

  • Why?


Summary

Summary

  • In this presentation, the following were covered:

    • Review of CIDR

    • Link-state routing protocols

    • OSPF backbone network design

    • OSPF and VLSM configurations

    • Functions of OSPF v2

    • Differences between distance vector and link- state network planning


  • Login