Basic router configuration
-
Upload
sourabh-badve -
Category
Documents
-
view
845 -
download
6
description
Transcript of Basic router configuration
Basic Router Configuration
BYMr.Sourabh S. Badve
Chapter Objectives
Explain IGRP Explain EIGRP Explain OSPF
Recall - I The different metrics used by the routing protocols
include: Hops Bandwidth Load cost Reliability
Interior routing protocols include: Routing Information Protocol (RIP) Open Shortest Path First (OSPF) Interior Gateway Routing Protocol (IGRP)
Recall - II Enhanced Interior Gateway Routing Protocol
(EIGRP) Intermediate System to Intermediate System (IS – IS)
The different RIP timers include: Route update timer Route invalid timer Holddown timer Route Flush timer
Routing tables can be defined as the database that contains the routing information of the network
Interior Gateway Routing Protocol (IGRP) IGRP is a distance-vector routing protocol The characteristics if IGRP include:
Uses composite metric Supports unequal-cost load balancing Supports multipath routing Supports holddowns Supports split horizons
Verifying IGRP Commands to verify IGRP configurations include:
show ip route show protocols show ip protocols debug ip rip debug ip igrp events debug ip igrp transactions
Debugging IGRP The debugging command displays the routing
information and the updates sent and received on the router
Commands for debugging IGRP include: debug ip igrp events debug ip igrp transactions
Enhanced Interior Gateway Routing Protocols (EIGRP) EIGRP saves all the routes connected to the
neighboring routers EIGRP has the qualities of both distance-vector and
link state protocols EIGRP is an ideal protocol in the large networks
Diffusing Update Algorithm (DUAL) DUAL helps the router to determine the best route to
the destination using the hop count, bandwidth and other factors as metrics
It sends query packets to the neighboring routers to determine the best path to reach the destination network
When a router receives a reply, DUAL calculates the successor (main route) and the feasible successor (backup route)
Route Discovery and Maintenance For discovering the routes, the tables used by
EIGRP include: Neighbor table Topology table Route table Successors Feasible successors
Unlike the other protocols, EIGRP uses four metrics, bandwidth, delay, load and reliability to determine the best path to transmit the packets
Verifying EIGRP Commands to verify EIGRP configurations include:
show ip route show ip route eigrp show ip eigrp neighbors show ip eigrp topology
Border Gateway Protocol BGP is an Exterior Gateway Protocol used to
exchange the routing information between two or more Autonomous Systems (AS)
It uses cost as its metrics The hosts that use BGP as their routing protocol,
exchange information with the help of TCP/IP It uses the method of Classless Inter-Domain
Routing (CIDR)
Link State Routing Protocols In Link-state routing, the routers while
communicating share the status of the links on the network
The protocols send Link State Advertisement (LSA) that contains routing information and details of the router that sent the information
The destination router stores the LSAs in a local database
When a change occurs in the database, the router runs the Shortest Path First (SPF) algorithm
Open Shortest Path First (OSPF) OSPF uses the link-state concept and sends Link
State Advertisements (LSAs) to all the connected routers
Entities of the OSPF hierarchy include: Autonomous System (AS) Areas Backbone Area
Area Border Routers (ABRs) Stub Area Autonomous System Boundary Router (ASBRs)
OSPF Hierarchy
Case StudyThe Hyderabad branch of the Blue Diamond Steel Company has 15 routers connected in the network. The network uses RIP to route the packets between the departments. Now the company has decided to add a team of 20 Software Engineers to design the new steel plants. The network administrator has decided to place the engineers on a different network. This requires the 16th router to be placed in the network.
Problem
The other departments cannot exchange the data with the software engineers
Solution
The network administrator decided to use OSPF, which uses bandwidth as its metric to route the
packets and can be used to connect large networks
Intermediate System to Intermediate System (IS – IS) IS – IS is a link state routing protocol used to carry
IP network information The routing in IS – IS is carried out in two levels:
Level 1 comprises of the routers connected in an area
Level 2 comprises of routers connected to the routers in multiple areas
Verifying OSPF Commands to verify OSPF configurations include:
show ip route show ip ospf show ip ospf database show ip ospf interface show ip protocols
Summary - I IGRP is a distant-vector routing protocol, which
implies that each router sends all or a part of its routing table in a routing message update
The characteristics of IGRP are: Uses composite metric Supports unequal-cost load balancing Supports multipath routing Supports multipath routing Supports holdown Supports split horizons
Summary - II The characteristics of EIGRP are:
Fast convergence Link-state protocol Less network overhead Interoperation with IGRP Supports three routed protocols Six path load-balancing
The Open Shortest Path First (OSPF) is a link-state routing protocol, used to handle routing for Internet Protocol (IP) traffic
Summary - III The OSPF protocol is designed on the Shortest
Path First (SPF) algorithm, which enables to determine the shortest route to each destination
OSPF provides the following advantages: Open protocol Loop free topology Scalable Hierarchical design Provides multicasting
Summary - IV The OSPF maintains a two-layer hierarchy
consisting of: Backbone area Off backbone
The advantage of dividing OSPF into areas are as follows: Conserves router resources Concealing information Dealing with external routes
Summary - V There are different OSPF area types that help to
handle external routes: Normal area Stub area Totally stubby area Not-so-stubby area