SEMINAR REPORT ON

ROUTER AND ROUTING

INTRODUCTION

There are many different computing and networking technologies some available today, some just now emerging; some well-proven, some quite experimental. Understanding and solving today's computing dilemma more completely involves recognizing technologies; especially since a single technology by itself seldom suffices and, instead, multiple technologies are usually necessary. Some technologies are being obsolete, some are maturing, some are adequate, and some are vital.This project describes the Router, its various types, the internal structure as well as the various functionalities of the Router. Router is a Layer 3 device. Therefore layer 3 security is managed through Router. Through this project various types of routing protocols are discussed. These routing protocols are the key for proper communication between routers. As Router is used as a device to establish a connection between different networks, these routing protocols are the methods used to communicate.

ROUTER

• A Router is a device that connects two networks – frequently over large distances.

• Routers have separate collision domain and separate broadcast domain for each port.

• A Router is a programmable device that works with other routers ,via routing protocol to establish the best path ,to forward a packet with a given address.

• Routers operate at least at 3rd layer ,the Network Layer ,of the OSI Reference Model.

FUNCTIONS OF ROUTER

1. Sends a packet of information from one network to

another network.

2. To route, builds routing table which contain-

o The destination network and subnet mask

o The next hop router to get to the destination network

o Routing metrics and administrative distance

TYPES OF ROUTERS

1. ACCESS LAYER ROUTER

Located at customer sites such as branch offices that do not need hierarchical routing of information. Routers Series:1600,1700,1800

2. DISTRIBUTION LAYER ROUTER

Distribution routers aggregate traffic from multiple access routers, either at the same site, or to collect the data streams from multiple sites to a major enterprise location. Router Series:2600,2800,3600

3. CORE LAYER ROUTER

Core router may provide a “Collapsed Backbone "interconnecting the distribution tier routers from multiple buildings of a campus, or large enterprise location.Router Series: 7200,7600,10000

ADVANTAGES OF ROUTERS

Routers use logical addressing, they provide many advantages over bridges and switches, including:

• Routers solve problems of broadcast .

• Routers separate bandwidth and collision domains.

• Routers allow you to connect different media types together, like Ethernet and Token Ring without any conversion issues.

• Routers can switch packets on the same interface using VLANs.

• Routers are more complex to configure, and require routing software for each high-level protocol suite that you need to route.

• Routing software decrypts the encrypted data, so it is vulnerable period during which attacker can attack within the router.

• Routers need to be configured to enable incoming connection to a certain computer depending on the protocol.

DISADVANTAGES OF ROUTERS

ROUTING

Routing is the act of moving information across an internetwork from a source to destination. Routing involves two basic activities: determining optimal routing paths and transporting information groups.

TYPES OF ROUTES

1. STATIC ROUTES- a route that is manually configured on the router.

2. DYNAMIC ROUTES- routes that a router learns by running a routing protocol.

3. DEFAULT ROUTES- a default route specifies a path that a router should use if it does n’t know how to reach the destination.

We have defined mainly four algorithms which are as below:

1. STATIC VERSUS DYNAMIC

Static Routing Systems cannot react to network changes ,whereas dynamic routing algorithms adjusts to changing network circumstances by analyzing incoming routing update messages.

2. SINGLE PATH VERSUS MULTIPATH

Unlike single path algorithms, these multipath algorithms permit traffic multiplexing over multiple lines.

ROUTING ALGORITHMS

3. INTRA DOMAIN VERSUS INTER DOMAIN

Some routing algorithms work only within domain while other works within and between the domain.

4. LINK STATE VERSUS DISTANCE VECTOR

Link state algorithms also known as shortest path first algorithm, flood routing information to all nodes in the internetwork.Distance vector also known as Bellman-Ford algorithm, call for each router to send some or all information of its routing table but only to its neighbors.

ROUTING PROTOCOLS

IGRP (INTERIOR GATEWAY ROUTING PROTOCOL)

• IGRP sends out periodic routing updates (every 90 seconds)

• IGRP sends out the full routing table every periodic updates

• IGRP uses a form of distance as its metric

• IGRP routes have an administrative distance of 100

• IGRP ,by default supports a maximum of 100 hops

• IGRP uses the Bellman-Ford Distance Vector algorithm to determine the best path

OSPF(OPEN SHORTEST PATH FIRST)

• OSPF will form neighbor relationships with adjacent routers in the same area.

• OSPF uses the Dijkstra Shortest Path First algorithm to determine the shortest path.

• OSPF is a classless protocol, and thus supports VLSMs.

• OSPF routes have an administrative distance is 110.

• OSPF uses cost as its metric.

THANK YOU !