GNS3 & VirtualBox on Mac

From FrogspawnWiki

Contents 1 Install TunTap 2 GNS3 Config 3 VirtualBox Config 4 References

This is an elaboration of my blog post about getting Dynamips running with VMWare on Linux. This article relates to getting GNS3 (fancy graphical interface to Dynamips) running with VirtualBox (a free vmware like program by Oracle) playing together nicely on a Mac.

The key difference in the process is that on a Mac you need to use a tap interface rather than the vmnet or vboxnet interface. The tap interface is a loopback interface so what you'll do is have Dynamips (via GNS3) bind to it and have VirtualBox use it as a bridged interface.

As a starting point I'm going to assume you have VirtualBox and GNS3 downloaded and running (although not talking to each other obviously).

Install TunTap

The first step will be to install tuntaposx. You can download from the project's homepage or use ports to install it.

Mac:~ $ sudo port install tuntaposx
Password:
--->  Fetching tuntaposx
--->  Attempting to fetch tuntap_20090913_src.tar.gz from http://lil.fr.distfiles.macports.org/tuntaposx
--->  Verifying checksum(s) for tuntaposx
--->  Extracting tuntaposx
--->  Applying patches to tuntaposx
--->  Configuring tuntaposx
--->  Building tuntaposx
--->  Staging tuntaposx into destroot
--->  Creating launchd control script
###########################################################
# A startup item has been generated that will aid in
# starting tuntaposx with launchd. It is disabled
# by default. Execute the following command to start it,
# and to cause it to launch at startup:
#
# sudo port load tuntaposx
###########################################################
Note: tuntaposx installs files outside the common directory structure.
--->  Installing tuntaposx @20090913_1+universal
--->  Activating tuntaposx @20090913_1+universal
--->  Cleaning tuntaposx
Mac:~ $ sudo port load tuntaposx
Mac:~ $

And that bit is done.

GNS3 Config

1. Create a cloud in GNS3.
2. Right click it and configure it.
3. Go to the "NIO TAP" tab.
4. Enter the full path to a tap interface (e.g. /dev/tap0).
5. Click "Add"

Now all you need to do is draw a Fast Ethernet connection from your router to your cloud and select the tap interface when prompted.

VirtualBox Config

Configure your virtualbox guest to have a bridged interface to your tap interface.

Simple as.

References

TAP devices on OS X - how to on the virtualbox.org forums

How to connect GNS3 to the internet in MacOSX on blindhog.net goes a bit further including hwo to configure NAT for the tap interfaces to get the dynamips routers out to the internet.

Install GNS3 on Mac OSX Leopard an article on EtherealMind.com by Greg Ferro on getting GNS3 up and running on OS X