Network architects

Published: Last Edited:

This essay has been submitted by a student. This is not an example of the work written by our professional essay writers.

ISP Level Network with OSPF and EIGRP

1. Overview

Network architects wanted to build multiprotocol networks in the early 1990s were faced with a tough problem. Most of the protocols running in enterprise network had no scalable routing protocols that enabled the network architect to build reliable large networks. The older and proven routing protocols such as Routing Information Protocol (RIP) or Interior Gateway Routing Protocol (IGRP) were reliable, but slow, and the newer emerging routing protocols, such as Open Shortest Path First (OSPF), were complex and unproven in the field at that time. Cisco Systems decided to bridge the gap between the existing technology with a new routing protocol, named Enhanced Interior Gateway Routing Protocol (EIGRP),that combined the simplicity and reliability of the old routing protocols.

The purpose of this project is to check stability, performances in OSPF and EIGRP protocols with CISCO based large scale network. Network architects recommend mix protocols for large network. My attempt is to prove and find changes in OSPF and EIGRP configurations. This will help us to do select best configuration and it will avoid potentially expensive network outages.

2. Objectives

I am going to achieve following objectives in CISCO based large scale network. This network contains OSPF, BGP and EIGRP protocols. The OPNET Technology is using to do following things

a) Examination link utilizations and routing path.

b) Test network performance with help of flow analysis.

c) Visualize network to determine overloaded links.

d) Deploy application and investigate impact on network.

e) Identify network failover recovery by performing failure analysis.

3. Current Situation

At present, I have almost finished my network design part and I used most common CISCO router series for my network. My network simulation is almost similar to actual ISP level. I have tried to maintain all the configurations according to standards and procedures.

The network simulation contains following equipments and peripherals

* CISCO 7204 routers - 5 Routers

* CISCO 3640 routers - 24 Routers

* CISCO 2509 routers - 10 Routers

* CISCO 1601 routers - 4 Routers

* LAN networks - 10 Network.

The CISCO 7200 series routers take action as core routers in my network simulation. The BGP protocol has cond to these CISCO routers. OSPF, EIGRP were cond according to scenario. Three scenarios have found in this network simulation. Which are MIX configuration, OSPF configuration and EIGRP configuration. Other CISCO series of routers (CISCO 3640 routers, CISCO 2509 routers and CISCO 1601 routers) represent a distributed level. Final layer covered by 10 LAN networks. Basically customer sites and branch networks symbolize this access layer.

Three scenarios, namely MIX-Configuration, OSPF-Configuration and EIGRP-Configuration have build with mix protocols, OSPF protocol and EIGRP protocol respectively. The multi protocols means BGP, OSPF, EIGRP protocols contains network scenario.

The above shows the MIX-Configuration scenario. It contains OSPF, EIGRP and BGP protocols. The BGP has cond to core routers and OSPF, EIGRP helps to connect LAN networks.

4. Problem Areas

Last few weeks of time, I struggled with two or three major errors. One is the OPNET installation problem and other one is runtime error when running the simulation. Fortunately, my past experience and tech articles have solved all the problems.

Here, I got following error when I was running the simulation

<<< Recoverable Error >>>
Object repository construction failed
due to errors encountered by the binder program (bind_so_msvc)
T (0), EV (-), MOD (NONE), PROC (sim_load_repos_rebuild)
<<< Program Abort >>>
Error encountered rebuilding repository -- unable to proceed
T (0), EV (-), MOD (NONE), PROC (sim_load_repos_load)

I have referred lot of articles and at last added <stdmod> value to Network Simulation Repositories column and sort out the problem.

I have read following articles, web links to find a solution.




5. Next Goals

I have covered requirement analysis, network simulation design and implementation, EIGRP and OSPF configuration phases.

Following items / stages still left in my dissertation

* Collect OSPF, EGIRP Simulation data.

* Analysis of above results

* Conclusion

* Final report etc.

Next steps are more critical because I have to analysis all the simulation results and do select best configuration in CISCO based higher level network. Mainly I am going to use flow analysis, visual link loader, and live object / attribute difference tools to collect information.


I am running according to my project schedule. Therefore I hope to finish it on time. But I have to do more study to understand OPNET architure.

6. References

6.1 Books

1. Patrick J. Conlan, 2009. Cisco Network Professional's Advanced Internetworking Guide. Sybex.

2. WilliamR.Parkhurst,2002. Cisco OSPF Command and Configuration Handbook (CCIE Professional Development). Cisco Press.

3. Internetworking Technologies Handbook. Chapter 46. Cisco Press.

4. EIGRP Network Design and Solution. Cisco Press.

5. OPNET IT Guru Academic Edition.

6.2 Electronic Sources - Web Sites

1. CISCO System, 2009. Available at:

2. OPNET Technologies, 2009. Available at:


Appendix A - Glossary of Abbreviations

OSPF - Open Shortest Path First

EIGRP - Enhanced Interior Gateway Routing Protocol

ISP - Internet Service Provider

BGP - Border Gateway Protocol

RIP - Routing Information Protocol