GNS3 support many switching options - they range from unmanaged switches, to Cisco IOS switches, to Datacenter Nexus switches, to Etherswitch modules and then emerging technologies such as OpenFlow and SDN.
One common misconception about GNS3 is that GNS3 does not support advanced switching options. While this was true in the past, GNS3 now supports options such as:
- Port Security
- And many others.Complimentary campus technologies such as HSRP are also supported.
Your selection of image and platform will affect what is possible. Options include:
- Cisco IOSvL2
- Etherswitch module
- GNS3 built in switch
Recommended switching platform: Cisco VIRL IOSvL2
With a Cisco VIRL IOSvL2 image, you can configure and test a wide range of advanced switching features. Go here for a full list:
This is the official Cisco way of emulating a switch.
Basic_switching Etherswitch module
While an Etherswitch module does not support advanced layer 2 features, it does allow you to configure basic VLANs, Spanning Tree and other options.
IOU is a less resource intensive alternative to IOSvL2, but the images are not publicly available. You will need to get them from someone who works at Cisco. In addition, as this is a Cisco internal tool, IOU mages may be buggy and no support is available.
Unmanaged switching: GNS3 built in switch
Use this if all you need is a basic switch to connect devices in a GNS3 topology. You cannot configure this switch through a CLI, but you can set the number of ports supported on the switch and other basic settings.
It’s not running a switch OS, everything is emulated from scratch. This mean some protocol could be buggy. Use it only for basic operations
By leveraging GNS3 support for Docker, you can now add Open vSwitch to your GNS3 topologies. In order to do that, use this template:
You can also use switches from other vendors such as Cumulus, Extreme Networks and many more.
David Bombal (CCIE #11023 Emeritus) passed his Cisco Certified Internetwork Expert Routing and Switching exam in January 2003. David has the highest rated and most popular course in the GNS3 Academy: SDN and OpenFlow Introduction.
David's software tools and training have been downloaded +100,000 times. Many thousands of engineers like you use his tools and training on a regular basis.
David has developed over 20 courses for HP which are used worldwide. These include multiple SDN courses and HP ASE certification courses (4 day Instructor led training).
David's YouTube videos have been viewed +1 million times.
David has been training Cisco and networking courses for 15+ years and has delivered instructor led courses in various countries around the world covering a wide range of Cisco topics from CCNA to CCIE.
He has also personally developed Cisco engineer utilities such as the VPN Config Generator, software, training materials, EBooks, videos and other products which are used throughout the world.