Development of a Network Lab Virtualization

Virtual PC Simulator, or VPC is a simulator for GNS3 that allows simulation of up to 9 PCs. This program allows the user to ping or traceroute the PCs, or the other hosts/routers from the virtual PCs while running Dynamips.

This program only allows a few network commands such as:

• ip address
• show
• hist
• dhcp
• arp
• ping address
• echo
• conf port
• ?
• quit

However, even though you have saved your network topology and exported the configuration files that includes the IP addresses of each router, VPC does not save the details and has to be retyped again.

By looking at the .net file that is saved, it can show whether UDP or ethernet mode is used.

VPC, however, has no connection with Dynamips and Dynagen. It is just a program that allows the user to set IP addresses for PCs in a network topology in GNS3.

As Aaron has went to Hong Kong for his Chinese Orchestra trip, I shall update today’s post.

In GNS3, the GUI is separated by 4 areas. Mainly, the :

• Node Type Window
• Workspace Window
• Console Window
• Topology Summary

The Node Type Window shows of the various routers and nodes that allow the user to construct a network topology.

As the word says, the workspace window is where the user designs the network topology by clicking and dragging a node onto this window.

In the console window, it shows of the various nodes in the workspace and its current status.

The topology summary displays what device and which is connected to which device.

A router can be fitted with different types of ports by right-clicking the router, then selecting configuration. Select the router on the right box, then select the “Slots” tab. From the various drop down lists, you can select which and how many serial ports and fast ethernet ports required for that router.

By clicking on the “Start/Resume all IOS” button, which resembles a “Play” button, the serial links between the routers will turn green, indicating that serial interface is turned on. However, the processor will begin to slow down. This is due to the fact that Dynamips and Dynagen will “eat up” 100% of the CPU resources, therefore creating lag and slowing the CPU speed.

The workaround, which is through idle pc, can be done by right-clicking on a single router, then select idle PC. GNS3 will then calculate an idle pc value. A prompt will then appear, giving the user to select a list of choices. Select the number with the asterisk beside it as it is a potentially better idlepc value. You can check the CPU usage and notice it would have dropped as compared to before.

Also, GNS3 can also integrate the use of a program called the Virtual PC Simulator, or VPC. Using VPCs, it can save on memory and CPU cycles. VPCs can be integrated through the usage of the Symbol Library.