Table of Contents for
Packet Tracer Network Simulator

Version ebook / Retour

Cover image for bash Cookbook, 2nd Edition Packet Tracer Network Simulator by Jesin A Published by Packt Publishing, 2014
  1. Cover
  2. Table of Contents
  3. Packet Tracer Network Simulator
  4. Packet Tracer Network Simulator
  5. Credits
  6. About the Author
  7. About the Reviewers
  8. www.PacktPub.com
  9. Preface
  10. Who this book is for
  11. Conventions
  12. Reader feedback
  13. Customer support
  14. 1. Getting Started with Packet Tracer
  15. Installing Packet Tracer
  16. Interface overview
  17. Creating a simple topology
  18. Summary
  19. 2. Network Devices
  20. Customizing devices with modules
  21. Emulating WAN
  22. Accessing the CLI
  23. Summary
  24. 3. Generic IP End Devices
  25. Servers
  26. Other end devices
  27. Configuring end devices
  28. Summary
  29. 4. Creating a Network Topology
  30. Testing connectivity with PDUs
  31. Using the simulation mode
  32. Clustering a topology
  33. Summary
  34. 5. Navigating and Modifying the Physical Workspace
  35. Moving devices physically
  36. Managing cables and distances
  37. Customizing icons and backgrounds
  38. Summary
  39. 6. Configuring Routing with the CLI
  40. Dynamic routing protocols
  41. The Routing table
  42. Load sharing
  43. Summary
  44. 7. Border Gateway Protocol (BGP)
  45. BGP versus dynamic routing protocols
  46. Configuring BGP in Packet Tracer
  47. Summary
  48. 8. IPv6 on Packet Tracer
  49. IPv6 static and dynamic routing
  50. Using both IPv4 and IPv6
  51. Summary
  52. 9. Setting Up a Wireless Network
  53. Wireless networks and physical workspaces
  54. Summary
  55. 10. Configuring VLANs and Trunks
  56. InterVLAN routing with routers and layer 3 switches
  57. Switch-to-switch trunk links
  58. Analyzing broadcasts in the simulation mode
  59. Summary
  60. 11. Creating Packet Tracer Assessments
  61. The initial network
  62. The answer network
  63. Testing the activity
  64. Summary
  65. Index

Load sharing

In the topology we have being configuring throughout this chapter, we can find that each router has two paths to reach each destination. So how about seeing how routers use these multiple paths together and load balancing the traffic across them.

Load balancing with RIP

We take RIP first because we do not have to do anything specific for load balancing. If there are multiple paths to reach a network destination with the same metric, RIP automatically load balances them. We will be using an interface type known as loopback to achieve this. A loopback is a virtual interface that behaves like a real interface and takes IP addresses.

We'll use the same topology we've been using throughout this chapter, and just add an extra interface. On router R4, we will add a loopback interface by using the following steps:

  1. Unfortunately, it isn't possible to do this with the GUI, so go to the CLI tab of R4 and enter the following commands:
    R4(config)#interface loopback 0
R4(config-if)#ip address 192.168.100.0 255.255.255.0
  2. Now on the same router, let's enable this interface for RIP. Go to the RIP config mode and enter the network IP of this interface.
    R4(config)#router rip
R4(router-if)#network 192.168.100.0
  3. That's it, create a complex PDU that is sent every two seconds.
    Load balancing with RIP
  4. Switch over to the simulation mode and you'll find that the first packet takes the R1-R2-R4 route while the second takes the R1-R3-R4 route.

You can also see which routes are load balanced by looking into the following routing table:

Router>show ip route
R    192.168.30.0/24 [120/1] via 192.168.10.2, 00:00:12, FastEthernet0/0
R    192.168.40.0/24 [120/1] via 192.168.20.2, 00:00:14, FastEthernet0/1
R    192.168.100.0/24 [120/2] via 192.168.20.2, 00:00:08, FastEthernet0/1
                      [120/2] via 192.168.10.2, 00:00:08, FastEthernet0/0

Only the RIP routes are shown here. Note that the route 192.168.100.0/24 has two gateways; this indicates that traffic to this network is load balanced.

Load balancing with static routing

Static routing requires additional configuration for a route to be load balanced. Assign IP addresses to all physical interfaces and also configure loopback interfaces as explained in the RIP section. To configure a load balanced route with static routing, perform the following steps:

  1. Go to router R2 and R3 and configure a route to the R4 router's loopback interface by using the following commands:
    R2(config)#ip route 192.168.100.0 255.255.255.0 192.168.30.2
R3(config)#ip route 192.168.100.0 255.255.255.0 192.168.40.2
  2. Now for R1, we have to configure two routes to reach 192.168.100.0/24. We need to tell the router that there are two ways to get to the R4 router's loopback. We do this by using the following commands:
    R1(config)#ip route 192.168.100.0 255.255.255.0 192.168.10.2
R1(config)#ip route 192.168.100.0 255.255.255.0 192.168.20.2
  3. Use the same complex PDU to see how traffic is load balanced.

After this configuration, if you look at the routing table, you'll find the network 192.168.100.0/24 has two routes, similar to RIP.