Supervised by : Dr.ASHRAF MAZKOR Done by : Mayada Ahmed al- masre 0801043

Supervised by :Dr.ASHRAF MAZKORDone by : Mayada Ahmed al-masre 0801043

ROUTING PROTOCOL

Presentation points

Routers and the routing table .Routing Table (Router conf).Static and Dynamic RoutingRouting protocols .Routing protocols classification(Glossary)

.Interior gatway protocols (IGP) .

Distance vector protocols . Linked state protocols and Routing Process

Exterior gateway protocols.

Routers and the routing table

A router : is a computer, which have many of the same HW and SW components that are found in other computers including : CPU, RAM , ROM , OS. we can say the router is a computer with an OS and

hardware designed for the routing process specialize in sending packets over the data network.

RAM is used to store these components: IOS (Internetwork Operating System) . Running Configuration File. IP Routing Table. Others...

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Routing Table (router conf. )

Used to store route information about directly : A directly connected network. A remote network . Information about the networks :

network address and subnet mask IP address of next-hop router.

The router interface. Each router interface is a member

of a different network . Activated (no shutdown

command ).•R1(config)#interface Serial0/0•R1(config-if)#ip address 192.168.2.1 255.255.255.0 •R1(config-if)#no shutdown

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Static and Dynamic Routing

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Routing protocols

Set of processes, algorithms, and messages that are used to exchange routing information and populate the routing table .

The purpose of a routing protocol : Discovery of remote networks Maintaining up-to-date routing information Choosing the best path to destination networks

Operations of a dynamic routing protocol : The router sends and receives routing messages on its interfaces. The router shares routing messages and routing information with

other routers that are using the same routing protocol. Routers exchange routing information to learn about remote

networks. When a router detects a topology change the routing protocol can

advertise this change to other routers.

Routing protocols classification

Why , What , When

Some Glossary

Autonomous System (AS) -

known as a routing domain - is a

collection of routers under a common

administration.

Convergence :when all routers'

routing tables are at a state of

consistency(network has converged

when all routers have complete and

accurate information about the

network).

wildcard-mask : is the inverse of

the subnet mask.

Some Glossary

Administrative distance (AD) : is an integer value from 0 to 255. The lower the value the more preferred the route source

Metric : a value used by routing protocols to determine, which path or which routes are better than others (when multiple paths to the same remote network) Hop count. (RIP, IGRP & EIGRP) Bandwidth Load balancing. Delay . Reliability . Cost.

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Interior Gatway Protocols (IGP)

Distance vector protocols : router which use distance

vector routing protocols knows 2 things:• Distance to final destination.

• Vector, or direction, traffic should be directed.

Distance vector protocols properties :

Simple implementation and maintenance.

Low resource requirement.

Slow convergence .

Limited scalability .

Routing loop .

RIPv1, RIPv2, IGRP, and EIGRP

RIPv1 RIPv2Difference

•A classful.

•Does not support subnets or

VLSM

•Does not send subnet mask in

routing update (30 seconds, by

default)

•Routing updates are broadcast

•A classless .•Next hop address is included in updates•Routing updates are multicast•The use of authentication is an optionAutomatically summarize classful routes•More 2 extensions in message format (subnet mask field, next hop )

Similarities

Hop count is used as the metric for path selection(Max hop

count=15)

RIP’s default administrative distance (AD)is 120

2 message types : Request and Response message (subnet mask field, next

hop )

Use of timers to prevent routing loop

Use of split horizon or split horizon with poison reverse

Use of triggered updates

RIPv1, RIPv2

RIPv1, RIPv2

IGRP, and EIGRP

IGRP EIGRPDifference

•Bandwidth, delay, load and

reliability are used to create a

composite metric.

•Routing updates are broadcast

every 90 seconds .

•Metrics :bandwidth ,Delay ,relia

bility load.

•no periodic updates .•automatically summarize routes at classfull boundaries.•Encrypt routing information .•Metrics: Bandwidth, delay, reliability, load•uses PDM (Protocol Dependent Modules) to route several different protocols

Similarities

IGRP is the predecessor of EIGRP and is now obsolete.

Packet Types (Hello, Update ,Acknowledgment ).

IGRP, and EIGRP

Router(config )#router eigrp autonomous-system Router(config-router)#network network-address [wildcard-

mask]

Interior Gatway Protocols (IGP)

Linked state protocols: (SPF,if not necessarily the path with the least number of hops) and the routers use a database to construct a topology map of the network. Link :This is an interface on a router. Link state : This is the information about the state of the links.

Builds Topological map and fast Convergence and Use of LSP . Solution (LSA flooding ) Designated router (DR) : Router with the highest OSPF

interface priority, and Backup designated router (BDR) Router can independently determine the shortest

path to every network .Memory ,Processing and Bandwidth Requirements.OSPF (Open Shortest Path First )and IS_IS().

Link-State(LS) Routing Process

1. Each routers learns about its own directly connected networks

2. LS routers exchange hello packet to “meet” other directly connected LS

routers.

3. Each router builds its own Link State Packet (LSP) which includes

information about neighbors such as neighbor ID, link type, & bandwidth.

4. After the LSP is created the router floods it to all neighbors who then store

the information and then forward it until all routers have the same

information.

5. Once all the routers have received all the LSPs, the routers then construct

a topological map of the network which is used to determine the best

routes to a destination

Link-State(LS) DB

Open Shortest Path First (OSPF )

R1(config)#router ospf process-idRouter(config-router)#network network-address wildcard-ask area area-id OSPF uses cost as the metric when cost =( 108 / bandwidth)

The Practical To Clarify

Intermediate System-to-Intermediate System (IS_IS )

Metric : maximum path value (default), and three optional metrics (costs): delay, expense, and error.

Packet Header Format: hello ,(LSPs), and (SNPs)

Exterior gateway protocols

protocols can routing between different AS, commonly used between hosts on the Internet to exchange routing table information which contain : list of known routers. addresses they can reach Cost metric .

Packet format : message type.Ex.:Border Gateway Protocol ( BGP)

Routing protocol (Under study(future work

How migrating EIGRP to OSPF .OLSR (Optimized Link State Routing protocol) was

used as a routing protocol and NRL Mobile Network Emulator (MNE) for dynamic topology control and manipulation.

Multicast OSPF (MOSPF) was defined as an extension to the OSPF unicast routing protocol

Protocol-Independent Multicast (PIM) works with all existing unicast routing protocols.

Conclusions

Static Routing: Minimal CPU processing, administrator to understand, Easy to configure and more secure. But Configuration and maintenance is time-consuming ,manual reconfiguration .

Dynamic (Interior And Exterior ) Distance vector routing protocols :

routes are advertised as vectors of distance & direction. incomplete view of network topology. Generally, periodic updates.

Link state routing protocols : complete view of network topology is created. updates are not periodic. Difficulty: All nodes need to have a consistent view of the

network

Conclusions

Confusion about the terms routed protocol and routing protocol is common.

ROUTED PROTOCOLS are nothing more than data being transported across the networks.

ROUTING PROTOCOLS are the software that allow routers to dynamically advertise and learn routes.

According to the scale of network, you can select different protocol.

Some routing protocols are designed for use within an organization, while other routing protocols are designed for use between organizations.

Thank you

ANY QUESTION

Supervised by : Dr.ASHRAF MAZKOR Done by : Mayada Ahmed al- masre 0801043

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