This tutorial is a continuation of the virtual voice lab series. In this tutorial, you will add a dial-plan to the PSTN router that was added in the first part of the PSTN simulation lab. (more…)

This tutorial is a continuation of the virtual voice lab series. Unfortunately, the virtual voice lab has been a “work in progress” much longer than I had hoped it would be when I started it two years ago. In this tutorial, you will add a new router to your GNS3 topology. It will connect it to the HQ, BR1 and BR2 routers to simulate an Internet connection and the Public Switched Telephone Network (PSTN).


There is one caveat to this PSTN simulation… GNS3/Dynamips is not capable of simulating traditional analog or digital circuits. We will be simulating an Internet Telephony Service provider (ITSP). ITSPs have become increasingly popular in the past ~5 years. Basically, the PSTN router will route incoming calls to the branch routers and received outgoing calls from the branch routers over a SIP or H323 trunk.

I recently upgraded my lab machine from Ubuntu 8.10 to 9.04. After the upgrade, I noticed GNS3 was not able to open saved projects. I tried several different things before I finally uninstalled GNS3 using the Synaptic Package Manager and installed it manually from the GNS3 website. Below is a video to walk you through the steps.

Here at Blindhog.net, we have issued tutorials for connecting Windows or Linux to a physical network using gns3, but apparently, there is a little difference for MacOSX.  I recently received an email from one of our readers, Ivan Pletenev. Ivan describes how to connect GNS3 to internet through wifi-interface in MacOSX. You will find his writeup below. Thanks Ivan!


I apologize for the delay in posting the next tutorial in the virtual voice lab but I ran into a problem communicating from the HQ router to the host Ubuntu server. I thought I was able to communicate from the HQ router to the host during the Headquarters build tutorial….but I was wrong.


I just finished the video tutorial for the headquarters part of the virtual voice lab. This tutorial will basically walk you through adding all the devices for the headquarters location.

While poking around the new GNS3.net forum, I found two very interesting howto posts. Jeremy Grossman (gns3 author) describes the processes needed to bridge a wireless NIC to GNS3 using both Linux and Windows.

Here are the links:

Bridge with a Wireless NIC on Linux

Bridge with a Wireless NIC on Windows

In the Virtual Voice lab series, I am using an Ubuntu Linux environment.  To eliminate permissions issues, it is best that you run GNS3 as root.

Here are a couple issues I have experienced when running GNS3 as a normal user.

Not able to start dynamips.
Error msg: Can’t Connect to the hypervisor on port 7200

Not able to connect to a cloud object.
Error Msg: 206-unable to create Linux raw ethernet NIO
Error Msg: 206-unable to create Linux generic ethernet NIO
Error Msg: 206-unable to create UDP NIO



In this tutorial, you will learn how to build a Cisco switching lab … even though GNS3 cannot emulate a Cisco switch. I will show you how to use an NM-16ESW network module in a 3640 router to emulate a switching environment.


If you have used GNS3 for any amount of time at all, you have encountered this situation. It’s late and you have been working on your lastest lab for hours. You decide to save your work. Logically, you go to File > Save. Unfortunately, the topology is saved but the router configs are gone.



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