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Presented byDevendra Kumar

8th Sem. CP

Outline

• Distance VS. Link-State• Route selection• Link-State network (OSPF) • Link-State Operation • Basic OSPF configuration and verification

Distance Vector VS. Link-State

Route Selection

RIP

OSPF

Multiple-Area

OSPF Network

Single-Area

Terminology

• Link• Link-State• Link-State

db• Area• Cost• Routing

Table• Adjacency

db• DR / BDR

OSPF path cost

Cisco Default Value

OSPF Packet Header

Concept of link state routing

Cost (weight) in link state routing

Cost is applied only by routerCost is applied when packet leaves the router

Link state packet

Cost: weight (traffic, security level, link state)

Flooding of A’s LSP

Link state database

Costs in the Dijkstra algorithm

Shortest path calculation

Step1

Step2

Shortest path calculation

Step3

Step4

Shortest path calculation

Step5

Step6

Shortest path calculation – S7

Shortest path calculation – S8

Shortest path calculation – S9

Shortest path calculation – S10

Shortest path calculation – S11

Shortest path calculation – S12

Shortest path calculation – S13

Link state routing table for router A

Basic configuration

• Wildcard-Mask

• Area ID

Basic configuration - Loopback

• Setup Loopbacko Ensure that at least one is active (For stability)

Basic configuration - priority

• Setup priorityo For DR/BDR selection

OSPF verificationshow ip protocol show ip route

show ip ospf show ip ospf interfaceshow ip ospf databaseshow ip ospf neighbor detail

clear ip route * clear ip route a.b.c.d

debug ip ospf events debug ip ospf adj

Thank You

Queries