Showing results for 
Search instead for 
Did you mean: 

How to connect GNS3 cloud with local area network that has a public ip address

Hi guys,

I am having a problem connecting a gns3 cloud to my local pc that has a public ip address. Basically i bought a plan for a dedicated server and the provider gave me a public ip address to use on my server.

I know how to connect the gns3 cloud when it comes to private ip addressing (example local area connection ip -> cloud is connected on that connection-> a router in gns3 has an ip in that same range and if i give it a default route i can reach the internet)

Now since the ip address on the local area connection is public is there any trick that i can do to make the router from inside gns to access the internet?

Best Regards


Collin Clark

Here's what has worked for me.

Create a cloud with the interface that has the public IP

Connect the cloud to your GNS infrastructure

Add a default route in the GNS connected router and inject it into the IGP

I've done this but it doesn't seem to be working.

Lets say that the public ip address of my local area connection is

GNS gloud is connected on the fa0/0 interface of a router which has the ip

The default gateway is

I've added a default route in the router but it's still not working.

What's the .30 address? Your router's default gateway should point to

Maybe i didn't explain it the proper way..

I bought a plan from a company that gives you a dedicated server (hardware level not software).

Since the server is a physical equipment they supply a public ip address in order to be accessible directly to the outside world. Below is an example of the ip addressing the server has.


netmask /27

default gateway (the default gateway router or layer 3 switch whatever equipment it is, is installed in their building and it's not accessible by me)

They supply me with remote desktop username and password to be able to access it.

So i installed GNS in order to make my tests.

I connected local area connection (which as i said has a public ip) with gns cloud and the gns cloud to a router inside gns. From this point onwards my problem starts since i don't know what ip addressing i have to give to my router in gns in order to comunicate with the outside world.

Is there any way that i can create a loopback adapter and give it private ip addressing and share the internet with the local area connection?

Thank you.

So if i understand the whole thing, you have only one public IP which is

Which OS is your server running on ? If windows, you can :

I usually do that to connect some routers to my real home network when using a WIFI connection.

Yes only one public ip was provided.

OS is windows server 2008 r2

I forgot to mention that i am using Hyper-V and i already share my local area connection with the virtual network adapter of Hyper-V.

What i planned was to use gns in a virtual machine created on HYPER-V. but unfortunately Hyper-v doesn't allow promiscuous mode ( so i am unable to forward the traffic from (gns3 installed in a virtual machine that was created in Hyper-v) gns3 to the outside world.

I know that vmware supports this mode (promiscuous) on vsphere but unfortunately this dedicated server come preinstalled with windows server 2008 r2, and they don't support esxi, so i am in a "dead-end".

Is there any way that i can share both HYPER-V and loopback network adapters to the local area connection?

Do you have any other suggestions?

I might suggest that you create the loopback interface in your VM and share the "virtual" local area connection of the VM with the loopback.

In this topology the real connection will be shared to all your VM and inside a VM with GNS3 you re-share the connection.

Thanks maxime that solved my problem!

I can now ping the internet from inside gns.

However i am still having a problem with dns resolving. I' ve set ip name-server [ip address of the dns] but when i try to ping i receive the message "Unrecognized host or address....".

Am i missing something?