Development of a Network Lab Virtualization

VPCS, or Virtual PC Simulator, is a program that allows the virtual simulation of PCs for GNS3. However, it is not a part of GNS3. VPCS allows pinging to GNS3 and vice versa.

Since VPCS creates up to 9 virtual PCs, it takes up less memory and CPU speed as compared to using a router for a PC. Using routers for PCs in GNS3 will require the user to calculate idle pc time as it still has the functions of a router.

We completed Scenario 4 for our last scenario for our project. It consisted of Aaron’s computer with DSLinux in VMWare. This computer has no internet. Whereas for my computer, it is connected to a Linksys Wireless Router G where the internet is provided.

First, we did IP addressing for the various routers in the network diagram on my computer. Then, we configured RIP and NAT/PAT. We proceeded to do IP addressing on the DSLinux.

Upon completing those, we tried opening Mozilla Firefox on the DSLinux and the yahoo.com browser sucessfully loaded.

After Week 12, we feel that we have learnt a lot about Dynagen & Dynamips. Through the usage of GNS3, it has provided us with an even more easier understanding of Dynagen and Dynamips itself.

We feel that Dynagen and Dynamips has showed us what this program has for its features and capabilities. For example, like how we managed to allow internet access from one PC to another PC through the Dynamips Server and GNS3.

From our FYP, it has taught us a lot of stuff and I will most probably continue on learning Dynagen & Dynamips, together with GNS3 and VPCS.

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.

Recently, we installed GNS3 into our computers after uninstalling Dynagen and Dynamips.

What is GNS3?

GNS3 is somewhat similar to Packet Tracer. It provides a GUI for Dynagen and Dynamips. Instead of having to type commands through a notepad, GNS3 is a friendly program that allows you to click and drag routers, computers, switches or servers and create a network topology.

A router’s configuration mode can be accessed by just starting up the router and then selecting Console after right-clicking it. The console, is the same as typing inside the configuration of a router in Packet Tracer, with the exception of the change in a few of the commands.

In order to use a specific router however, you require the IOS of the router in .bin format. Then, you have to add the IOS into the program.

After creating your network topology and configuring it correctly, you can save the file into a .net format file.

Comparing GNS3 to manually creating the .net file, GNS3 is more suited to those that want to practise and have a go at how Dynagen and Dynamips work whereas manually typing the commands on a notepad is more suited to those who have an advanced knowledge on how to work with Dynagen and Dynamips.

Yesterday, we tried to do troubleshooting on the installation of dynamips and dynagen. Apparently, opening the .exe file gave an error. Mr Wagio then asked us to try copying the packet.dll and winpcap.dll files and paste them into the system32 folder. However, it did not work.

I took a look at the readme file and it said to paste the files into the system folder. That too, didn’t work. We thought it was due to the computer’s problem. Mr Wagio then asked us to download the various previous versions of winpcap installers on the website.

In total, I downloaded versions:

3.1-WinPcap
3.2.1-WinPcap
3.1.3-WinPcap
3.1.4-WinPcap
4.0-WinPcap
4.0.1-WinPcap
4.0.2-WinPcap

After uninstalling all the programs, and reinstalling in the order of WinPcap first, followed by the dynagen and dynamips package; and copying and pasting the packet.dll and winpcap.dll files to system32 and system folders, the program still couldn’t work and had the same error.

Today, we decided to install in Aaron’s laptop. And true enough, the first installation was sucessful without errors. We also started to read up on the configuration notes. We learned of things such as autostart. Also learned of how to set the default router model accordingly.

After installing Dynamips on the computer, we tried opening the file.

An error came out:

The procedure entry point PacketGetReadEvent could not be located in the dynamic link library packet.dll.

After a week of reading and researching on Dynamips and Dynagen, we finally managed to download the 2 files.

Apparently, the OS we were using were Debian-Linux. Therefore, in order to install the programs, we needed to have a basic knowledge on shell commands. After a fast and clear tutorial by Mr. Wagio on the few commands, we could install the programs on the other computer on our own. During the process, we learnt of shell commands such as “apt-cache search”, “apt-get install” and how to convert a file into an executable.

However, as we needed to do our reports on Microsoft Word and our slides on Microsoft Powerpoint, we reformatted our computers again to Windows XP Professional. This time, with the usage of a disk that had all the installation files for the drivers.

We managed to install Dynamips and Dynagen within a couple of minutes and will be trying it out tomorrow at the lab again.

We reformatted our computers and installed debian-linux on Wednesday for our project on the Development of Network Lab Virtualization. Aaron tried to install the Windows XP OS on his computer but we found out we had to redownload all of the drivers, which would be a very tiring task as the download speed of the internet in school was slow.

Anyway, back to debian. Debian is a free operating system composed entirely of free and open source software. Debian is somewhat similar to Windows. Web browsers such as Epiphany and Iceweasel are similar to Web Browsers in Windows such as Internet Explorer and Mozilla Firefox.

Next, we tried to download Dynamips and Dynagen from the internet. Apparently, I downloaded the wrong type of file. The files had .rpm and .tar.gz type. Files that had .rpm at the end were for usage in Red Hat while Debian uses .tar.gz to unzip files.

To install dynagen and dynamips, we had to install libpcap, which is used to provide bridging router interfaces to physical network cards.

Then, we need to extract dynagen and dynamips to a suitable location. Then we need to create symlinks, or symbolic links, to dynagen and dynamips executables. A symlink is somewhat like a shortcut to another directory.

It is a cisco router emulater that emulates 1700, 2600, 3600, 3700, and 7200 hardware platforms, and runs standard IOS images. the creator and writer of this emulator, Christophe Fillot, states that this emulator can be used as a training platform for people to be more familiar with cisco devices. It can also be used to check configuration quickly on routers before they are deployed on real routers. This emulator, however, cannot replace real routers and instead can be used as a complementary tool for administrators who want to pass their CCNA/ CCNP/ CCIE exams. Also, the performance of Dynamips is only 1 kpps as compared to the actual 100 kpps of a real router.

Dynamips does not emulate catalyst switches.

Dynagen, a text-based front end program written in Python, uses a “Hypervisor” mode to communicate with Dynamips. This program simplifies building and working with virtual networks.

Dynagen uses a simple configuration file for specifying virtual router hardware configurations.

It also uses simple syntaxes to interconnect routers, bridges, frame-relay and ATM, and Ethernet switches. It doesn’t require any dealing with NETIOS

Dynagen can run in a client / server mode. Simply, Dynagen can run on your workstation and communicate with Dynamips on a back-end server. 

Dynagen can also control multiple Dynamips server simultaneously for distributing large virtual networks across several machines.

Dynagen and Dynamips can also be run on the same system.

Dynagen can support commands such as start router, stop router, reload router, suspend router and telnet to another router.