GNS3 For Fun and Profit!

As some of you already know I am practicing for the CCNA Security. I made this topology for my own reference but I thought I should share it with everyone. Another goal of mine is to demonstrate the power of GNS3. This is my approach to a hybrid physical/virtual lab environment in GNS3. In preparation for the CCNA Security exam, I am going through the lab manual that is part of the Cisco Network Academy Curriculum. For the Chapter 9 lab in particular, part of the requirements for this lab is to perform spanning-tree and port security which simply cannot be done (even with the EtherSwitch) in GNS3. GNS3 cannot emulate layer 2 switches due to the complexity of emulating an ASIC chip. However, GNS3 does support routers which you can install a switch line card for layer 2 features. Despite having support for a layer 2 switch line card, many layer 2 features are not supported, such as: port security, Multiple Spanning Tree, Rapid Spanning Tree, and STP enhancements and more. With this limitation in mind, I decided to buy a couple 2960 Catalyst switches and then connect them both to a physical router. I won't explain the wiring as you can just look at my GNS3 topology below.

 

Logically, this design functions in GNS3 per the specifications detailed in the original lab topology. For reference, here is the original topology from the lab manual:

There are multiple ways to setup a lab like this. One way is to connect each device  (like illustrated above) to a separate NIC (I actually bought some USB Ethernet NIC's for this purpose). Another method is to use a "breakout switch." With a breakout switch you connect each physical device to a different switch port and assign to a separate vlan. You can then trunk the connections to the NIC on your pc/server (provided the NIC installed supports 802.1q trunking).

An example of a breakout switch design can be found here. In a subsequent post, I might illustrate a hybrid topology with the "breakout switch" design.

I can also combine my physical equipment with virtualized appliances like a Cisco PIX, ASA, and/or IDS. GNS3 even supports Juniper virtualization. GNS3 also has direct integration into Virtual Box. You can also do some neat stuff in VMware using a design as my topology above. All in all, the possibilities with GNS3 are virtually (no pun intended) endless. It's really neat stuff.

My end goal is to make a CCIE hybrid/virtual topology. This is only a stepping stone. I am also going to create another topology using Juniper/Cisco equipment in a physical/virtual environment.

Let me know if you have any questions in the comments below.