Cisco Nexus Gns3

Beginning of this year, i learned about the Nexus 9000V and I immediately saw the chance to use it for the CCIE DC preparation (and for some programming tests as well, but that’s for a future blogpost). The 9kV is basically a virtual Nexus 9300 that you can run on ESXi, Virtual BOX and KVM (the qcow2 Version is that one you need for GNS3.

Jan 16, 2020 GNS3 is more specific and professional than Cisco Packet Tracer. There is no need to add any Cisco devices to the Packet Tracer, but it is absolutely necessary to download and add the Cisco IOS for GNS3. You need to use GNS3 to use the actual Router and Switch IOS images. Learn how to configure switching in GNS3. In this video we discuss importing and configuring a Cisco Nexus 7k switch with GNS3.Free software worth $200: http. Sudo mv /home/gns3/OVMF-20160813.fd /usr/share/ovmf/ 4. Add the appliance Import the appliance file to GNS3 (guide, start from 'How to use a GNS3A file'). Drag the device into the topology (you'll find it in the Switches section); GNS3 will automatically upload the image to the GNS3 VM. Once the image is uploaded, start the instance, and have fun. Hi, I am using NX-OS92 9.2.1 image for my GNS3 lab on VMware. Eachtime I start my switch it goes to loader mode, I have tried boot (image.bin) sometimes it load but mostly it comes back to loader prompt. I have also different versions of the nexus image, but same issue. What is the issue here?

Here are the pro’s and con’s for the 9000V, because as always, where’s an upside, there’s also a downside.


  • Free for testing/training use (you do need a 9k Contract to get it from
  • You can simulate a lot, even VPC (since NX-OS 7.0(3)I5(2)) and much more … 😉
  • Also there are a lot of untested features, that “might” work (just have a look into the config guide)


  • No VXLan EVPN Support (but VXLan without EVPN should work)
  • You need power to run it, 8GB Ram and at least 1-2 CPUs (Cores) should be Available.
  • A few tweaks are necessary to get it running in GNS3.
  • Traffic through the 9kV is limited to 4mbit, but hey it’s a lab …

Cisco Nexus 9k Gns3

Here is the Link to the Configuration Guide, where you can Lookup all details: NX-OSv 9000 Guide

I don’t replicate the whole step for installing it, since Andras Dosztal does have a great guide on his blog to get you started: How to add NX-OSv 9000 to GNS3

Once you’ve done that, there are a few minor stumbling blocks:

  • The Nexus will boot the first time, but on the second it won’t find the image and is ending up in the loader. This is how to fix that:

config t
boot nxos nxos.7.0.3.I5.2.bin
copy running-config startup-config

  • Be sure to have enough RAM and CPU’s if you boot them at the same time. I had really strange behaviors before i granted every 9kv at least 8GB and 1CPU.
  • Another major thing is , some L2 Commands as “show mac address-table” are different. If you use the regular NX-OS you get wrong infos (you don’t see MAC addresses that are there)

So what is my first impression after spending a weekend playing around? The Nexus 9000V is an ABSOLUTELY great thing. It has it’s limitations, but for prepping for the EXAM i think this will help me out a lot. Of course it isn’t a full replacement and you have to be careful what’s working and what’s not. But that’s to find out in the next weeks.

So if you want to know more about the lab on the drawing? Stay tuned for the next Posting here! Just so much 80GB Ram, 16 CPU’s are a pretty good start, but I’m testing to how much i can limit the Ram, just so much 32GB are definitely too less. 🙂

July 14, 2014srijit

Here I am listing all the working versions of Cisco IOS which I have tested with the latest version of GNS3.

Update as on 14th May 2018 –

All the IOS, IOU, Nexus and other images has been updated, checked and verified with latest GNS3 & GSN3 VM. Download here –

Feel free to download them and use them for your Cisco certifications studies.


Old ones are kept intact for your reference-

  1. 1700 –
  2. 2600 –
  3. 2691 –
  4. 3640 –
  5. 3660 –
  6. 3725 –
  7. 3745 –
  8. 7200 (v15) –
  9. 7200p (v15) –

Mirror Links:


Cisco Nexus Gns3

Gns3 Cisco Switch Ios Images


Cisco Nexus Gns3 Controller

If you face any problem setting it up with GNS3 drop me a message and I will get back to you asap.

Cisco Gns3 Ios Images Downloads

GNS3 is an open source (GNU GPL) software that simulates complex networks while being as close as possible from the way real networks perform, all of this without having dedicated network hardware such as routers and switches.

GNS3 provides an intuitive graphical user interface to design and configure virtual networks, it runs on traditional PC hardware and may be used on multiple operating systems, including Windows, Linux, and Mac OS X.

In order to provide complete and accurate simulations, GNS3 actually uses the following emulators to run the very same operating systems as in real networks:

Cisco Nexus 9000 Gns3

  • Dynamips, the well known Cisco IOS emulator.
  • VirtualBox, runs desktop and server operating systems as well as Juniper JunOS.
  • QEMU, a generic open source machine emulator, it runs Cisco ASA, PIX and IPS.

Cisco Nexus 7000 Gns3

GNS3 is an excellent alternative or complementary tool to real labs for network engineers, administrators and people studying for certifications such as Cisco CCNA, CCNP andCCIE as well as Juniper JNCIA, JNCIS and JNCIE.