Migration between routing protocols in a specific environment Westminster LEA network and key issues of EIGRP

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Chapter 1


The idea for this project came after a personal experience with Westminster LEA office, during the last two years as for most my phone calls to them answered by (" the network is down we cannot use the system " ) at this time I thought of ideas to improve they system and reduce the downtime and my main interest was to take a discussion whether to implement an advanced distance-vector routing protocol, networking protocol such as EIGRP to replace the existent distance-vector routing protocol RIPv2 would bring advantages to the operations of the network.

This project presents, in easy terms, all steps necessary for a successful migration between routing protocols in a specific environment Westminster LEA network and discover the key issues of EIGRP and compares it with other Interior Gateway Routing Protocols..

This report is written with the aim to discover these advantages and disadvantages and present the results of a theoretical migration from RIPv2 to EIGRP, in a simulated network of four Cisco routers that plan, in very small scale, to represent the network of the LEA communicating to other part of the Westminster council departments at its core and access layers. The intent is to demonstrate practically how distance-vector and advanced distance-vector routing work; in what they are essentially different; how they are implemented; and how they can achieve very different results in the same network topology, and the EIGRP advantages of using advanced distance-vector and it's great features such as Multiple network-layer protocols, Rapid convergence, Reduced bandwidth usage

The aim of this project is to guide the reader with basic knowledge of networking to understand the reasons behind the migration between the two protocols up to understanding the advantage and the disadvantage of using EIGRP.

Chapter 2

2.1 Literature Review

This is proposal focused on understanding o EIGRP routing protocols concepts. However, EIGRP is Enhanced Interior Gateway Routing Protocol (EIGRP) is a Cisco-proprietary routing protocol based on IGRP, but EIGRP's wide features and lightning fast convergence set it apart from its predecessor. Unlike IGRP, which is a classful routing protocol, Cisco released EIGRP in 1994 as a scalable, improved version of its proprietary, based on advanced distance-vector routing protocol, IGRP, and EIGRP are compatible, although EIGRP offers multiprotocol support and IGRP does not, By default, the EIGRP composite metric is a 32-bit quantity that is a sum of the segment delays and the lowest segment bandwidth, and IGRP uses a 24-bit metric, by multiplying or dividing by 256, EIGRP can easily exchange information with IGRP, EIGRP also imposes a maximum hop limit of 224, slightly less than IGRP's generous 255 Redistribution is automatic between IGRP and EIGRP as long as both processes use the same autonomous system (AS) number.[Reference me], EIGRP is been used by big originations because it easy to configure (i.e user friendly) and it has great feature to gave the ability of expanding , EIGRP is the primary routing protocol that accommodates, IPX/SPX (Novell Netware) , Apple talk, & IP (Internet Protocol) protocols systems (i.e. it is compatible with diverse protocol in the primary level).

2.1.2 Characteristics of EIGRP

· Hybrid Protocol / Hybrid Routing refers to 'balanced-hybrid' routing; a combination of distance-vector routing, which works by sharing its knowledge of the entire network with its neighbours, and link-state routing, where the router informs every router on the network about its closest neighbours, In another word EIGRP is distance vector protocal that has link sate protocol characteristics. i

* EIGR by default has automatic summarization on the class boundary enabled, however one of EIGRPs great features is enabling the user to turn the auto-summarization off and configure manual summarization.

• EIGRP works well in large networks, because EIGRP is considered to be a hybrid routing protocol, as it has distance vector as well as link-state characteristics.

• Sends Hello packets every 5secounds and hold down timer is 15 second in another ward EIGRP send three hello packets to it is neighbour before declaring the neighbor as unreachable (this for fast speed links, such as LANs and fast WANs using multicast ), and it sends Hello packets every 60 second with hold down time of 180 seconds generally WAN links considered as slow link (except point-to-point sub-interfaces).

• EIGRP was developed for use in bigger networks, as its maximum hop count is 255 hops.

• In addition to this it supports IP, IPX and Apple talk, VLSM AND CIDR it has the ability to efficiently discover neighbors, and is also considered classless] ii

• EIGRP supports for authentication via Message-Digest algorithm 5 (MD5) only, and MD5 is cryptography which is commonly used to cryptographic to check the reliability of files and MD5 is not collision resistant.[**1]

• Default AD (administrative distance) is 90 (AD is the measure used by Cisco routers to choose the best path when there are two or more routes to the same destination from two different routing protocols.)

• Uses algorithm called Diffusing Update Algorithm (DUAL ) to prevent loops, Dual sends queries looking for a loop-free route to the subnet in question. When a new route is found, DUAL adds it to the routing table. The EIGRP DUAL process uses messages to make sure that a route exists, and not create a loop, before replacing a failed route with an alternative route. DUAL also allows a router running EIGRP to find alternate paths without waiting on updates from other routers.

• EIGRP combination Metrics is based on a range of values such as Bandwidth, Delay, Load, and Reliability

• EIGRP uses independent system numbers to classify groups of routers that share route information. Only routers that have the same independent system numbers share routes.

• EIGRP has maximum 255 of hop count, by default it is 100 hop in the final IOS released by Cisco but the router can be configured to accommodate up to 255hops.

• In large networks it is common to come across complicated topology and route tables. This can reduce convergence speed whilst distributing calculation procedures.iii

2.1.3 Features:

EIGRP contain a number of features that are not found in other distance vector routing protocols like RIP (RIPv1 and RIPv2)

• One of its best features is the Unequal-cost load balancing feature. Unlike OSPF this is the same as IGRP.

• It's Classless Routing Protocol or VLSM / CIDR give it special advantages over RIPv2.

• EIGRP improves scalability due to it's use of Diffusing Update Algorithm (DUAL).

DUAL protocol ensures fast convergence and looks for the most efficient loop-free route advertised by neighbors. These advertised lists are added to the router's routing table, allowing EIGRP to have better handling of routing loops and rapid convergence.

• It's Multiprotocol supports TCP/IP, IPX/SPX and AppleTalk

• It provides efficient use of Bandwidth

• It increment updates only to the routers that need them. This technique is referred to as 'partial bounded updates'.

• It uses 'Hello' packets this hello packets by default use no more than 50% of the link's bandwidth EIGRP packets. This is referred to as 'minimal bandwidth consumption'.

• PDM (Protocol Dependent Module)

• Keeps EIGRP as modular

• Different PDMs can be added to EIGRP as new routed protocols are enhanced or developed: IPv4, IPv6, IPX, and AppleTalk

• EIGRP is protocol independent[rf]

These features include: { I think I have to re-evaluate the features of EIGRP}

• Reliable Transport Protocol (RTP)

• Establishing Adjacencies { I have this below just I need to put them in order}

• Neighbor and Topology Tables { I have this below just I need to put them in order }


Reliability has the capability to use TCP based transmission when it is necessary to guarantee that a neighbor received a communication.

By default EIGRP does not use TCP and Cisco do not recommend using Reliability and Load since the bandwidth itself is variable. In other words Cisco has designed a mechanism that leverages multicasts and unicasts in order to deliver updates quickly and track the receipt of the data. Moreover EIGRP uses Reliable Transport Protocol (RTP). When EIGRP sends multicast traffic it uses the Class D address

Each EIGRP router is aware of who its neighbors are, and for each multicast it sends out, it maintains a list of the neighbors who have replied. It will change dynamically causing the EIGRP protocol to recalculate the routes using CPU cycles allowing the device to cool off. By default only bandwidth and delay are used to exchange packets.

Key Points;

• Reliability is measure dynamically

• EIGRP uses error rate for measurement

• 66666666 reflects the total outgoing error rates of the interfaces along the route

• PDM5 is calculated on a five minute weighted average, so as not to allow sudden peaks and valleys to make a significant impact.

This is expressed as an 8 bit number.66666666

• 255 is a 100% reliable link


Load is measured dynamically.

It uses channel occupancy for measurement and reflects the total outgoing load of the interfaces along the route.

It is calculated on a five minute weighted average, so as not to allow sudden peaks and valleys to make a significant impact.6666666666666

Expressed as an 8 bit number

255 is a 100% loaded link

EIGRP routers keep route and topology information instantly available in RAM in order for them to respond rapidly to changes. Like OSPF, EIGRP keeps this information in several tables, or databases. The following terms are related to EIGRP tables:

EIGRP tables

• Neighbor table - Each EIGRP router sustains a neighbor table that records adjacent routers. This table is similar to the adjacency database used by OSPF. There is a neighbor table for each protocol that EIGRP supports.

• Topology table - Every EIGRP router sustains a topology table for each configured network protocol. These tables include route entries for all destinations that the router is familiar with. All learned routes to a destination are recorded in the topology table.

• Routing table - EIGRP chooses the best routes to a destination from the topology table and places these routes in the routing table. Each EIGRP router maintains a routing table for each network protocol.

• EIGRP routing updates are activated only if a change occurs in the network topology For example if an interface goes up or down, or if either the IP address changes bandwidth or the delay changes then EIGRP routing updates would be activated.

• Successor - A successor is a route selected as the primary route to use in order to reach a destination.

Successor entries are kept in the routing table. Multiple successors for a destination can be retained in the routing table.

• Feasible successor - A feasible successor is a backup route. These routes are selected simultaneously to successors being identified, but are kept in the topology table. Multiple feasible successors for a destination can be retained in the topology table.

• Protocol Dependent Modules 77777777777777

2.1.4 EIGRP Security n/* chnge me */

• IGRP had no security but EIGRP has some

• Port scan for IP protocol 88 to

• Potential DOS when sending router lots of EIGRP neighbor announcements with spoofed source IP addresses, the router will ARP storm the destination if it is on the LAN

• EIGRP does not use plain text authentication

• IP EIGRP route authentication provides Message Digest 5 (MD5) authentication of routing updates from the IP EIGRP routing protocol. (IOS 11.3 and later)

• The MD5 keyed digest in each Enhanced IGRP packet prevents the introduction of unauthorized or false routing messages from unapproved sources.

Chapter 3

Aims and Objectives

This section of the report is a critical analysis and evaluation of EIGRP how EIGRP is much more efficient and faster in reaching convergence than RIPv2 and a more scalable routing protocol.

3.1 Aims:

This project has developed around the following major aims;

3.1.1 Aim 1

• To gain a better understanding of EIGRP routing protocol, explore the advantages and present the results of a theoretical migration from RIPv2 to EIGRP by demonstrating performance of a distance-vector protocol RIPv2 and an advanced distance-vector routing protocol such as EIGRP, moreover to demonstrate each protocol individually pointing to the main deference between EIGRP and RIP

3.1.2 Aim 2

To compare EIGRP to other routing protocols such as OSPF

• To give an initial overview of IP addressing features, including considerations on public and private IP addresses, classful and classless addressing, method of, CIDR and summarisation and VLSM To progress individual network design, configuration and troubleshooting skills.

3.1.3 Aim 3

Building a network based on EIGRP;

This will be achieved firstly by using a packet tracer which will then be applied to four Cisco routers. Four routers is an ideal number when building a smaller network.

• To gain a better understanding of IP interior gateway protocols and especially of EIGRP,

• To improve personal network design, configuration and troubleshooting skills.

• To design, build up, configure, test and troubleshoot a simulated topology of Westminster LEA in our labs at London Metropolitan university

3.2 Objectives :

• To explain EIGRP concepts

• investigating into EIGRP concepts, technology, and it's Compatibility

• To identify EIGRP Terminology 7777777777

• Implementing the EIGRP

• Evaluate the finding

Chapter 4 part 1

4.1 Scope ( how to archive this project write about how u'll do the project)

From Hillal :

• Books

• Website

• Journals

From G:




4.2 EIGRP Terminology(take this to the Literature Review)

Chapter 4 part 2

4.2.1 Approach ( how you'll do it )

• Investigate the main EIGRP features to have a good understanding, then compare and critically analyse them

• To show the need for diffuse Update Algorithm (DUAL) ensures that a given route is recalculated globally whenever it might cause a routing loop.

• To achieve this network will be set up first in a simulation in packet tracer then it will be implemented over real network routers.

• Compeer the features of EIGRP to the other routing protocols

Work breakdown structure


An intruder can effectively use vulnerabilities of interior routing protocols, such as EIGRP or OSPF, to plant Trojan horse servers into your network or to disrupt your core links with a denial-of-service attack. The vulnerability of EIGRP arises from the fact that the routing information exchange is not authenticated and is easy to spoof. MD5 authentication of EIGRP packets can ensure that the routers accept only packets signed by their trusted peers. The MD5 authentication prevents man-in-th e-middle attacks or route spoofing and offers only authenticity, not confidentiality. The EIGRP MD5 authentication uses shared secret (key) between adjacent routers to generate MD5 fingerprints from EIGRP information and the shared secret. The MD5 fingerprints generated in this way are very hard to forge without knowing the shared secret, leading to a very high level of authenticity. In a secure network design, you should use different keys that are frequently changed in each IP subnet. Distribute keys in a secure network through a secure protected session.


1- i https://learningnetwork.cisco.com/thread/7536 (searched date the 13/12/2009)

2- ii http://www.beginlinux.org/mod/resource/view.php?id=2911 (searched date 13/12/2009)

3- iii http://www.ciscotests.org/ccna.php?part=7 (searched date 13/12/2009)

4- iiii EIGRP Network Design Solutions (page 15)

5- [**1] http://www.ietf.org/rfc/rfc1321.txt (searched date 09/12/2009)

6- http://www.cisco.com

Mythology {{ type how your going to reach the goals( how Ur going to do your objectives) eg if Ur compering EIGRP with RIP how Ur going to do it }}