Download the Internet appliance from the GNS3 website

Import GNS3 appliance

Configure the GNS3 network:

Last updated
August 3, 2017

David Bombal
Julien Duponchelle
Edit this Article
Last updated
August 3, 2017

David Bombal
Julien Duponchelle
Edit this Article

Connect GNS3 to the Internet (GNS3 VM)


This document explains how to connect GNS3 topologies to the Internet.

This document explains how to connect GNS3 topologies to the Internet when using the GNS3 VM.

Note If you are using a local install of GNS3, refer to this document.

The topology created in this document looks as follows:

WARNING Ensure that your PC firewall is not blocking GNS3 traffic. If necessary, turn off your PC’s firewall.

Download the Internet appliance from the GNS3 website

  1. Using a web browser, browse to and click the MARKETPLACE menu item:

  1. Click Appliances:

  1. Select the Internet for GNS3 VM appliance:        

  1. An appliance description is displayed. Confirm details of the appliance and then click Download Template:

  1. The appliance is downloaded to your local PC:

Import GNS3 appliance

NOTEThis document assumes that you already have both the GNS3 Graphical User Interface installed (GNS3-all-in-one) and the GNS3 VM integrated with GNS3. Please refer to other guides for more details on how to install the GNS3 all-in-one package and how to download and configure the GNS3 VM.

  1. Create a new GNS3 topology:


  1. Name the project and click OK:. In this example, the name GNS3-VM-Internet is used:



  1. In the GNS3 user interface, click File and then Import appliance:

  1. Navigate to your Downloads folder, select the internet.gns3a appliance and then click Open:

  1. The Internet window displays. Review the summary information: “This appliance simulates a domestic modem. It provides IP addresses using DHCP and will NAT all connections to the Internet without you having to use a cloud interface in your GNS3 topologies. The IP subnets used are in the range. Multiple internets can be configured and will have different IP address ranges from to”

Click Next >:

  1. Select the Run the appliance on the GNS VM (recommend) Server type because the GNS3 VM is required for this server type.

Click Next > :

  1. An operating system is bundled with the Internet new appliance. Click Next >:

  1. A confirmation prompt is displayed. Click Yes to install the appliance:

  1. A Summary of settings are displayed. Click Next > to continue:

  1. A Usage screen is displayed. Click Finish to complete the appliance addition

  1. The appliance is added to GNS3 and a success message displayed. Click OK:

  1. Click the Browse all Devices menu option to view the newly imported GNS3 appliance:

  1. OptionalYou can view the appliance settings by clicking Edit and then Preferences:

  1. Optional Click on the appliance type (will vary) to view the appliance details:

  1. Once you have imported the new appliance into GNS3, you can create topologies which include the new appliance. Drag and drop the Internet 0.1 appliance from the GNS3 Toolbar to the GNS3 Workspace. You may be prompted to upload the appliance operating system to the GNS3 VM. Click Yes to upload the appliance operating system.

  1. The appliance operating system is uploaded to the GNS3 VM

  1. To add a router to the GNS3 topology, clickn the Routers button on the Devices_Toolbar

  1. The routers available will depend on your GNS3 configuration. In this example both a local router and GNS3 VM router are available.

  1. Drag and drop a GNS3 VM router to the GNS3 Workspace. An instance of the node becomes available in the Workspace:

  1. Drag and drop another local router to the GNS3 Workspace:

  1. Click the Toolbar Device button again to collapse the group:

  1. Click the Add a Link button to start adding links to your topology. The mouse cursor will change to indicate that links can be added:

  1. Click on the first router topology to display available interfaces (this is device dependant):

  1. Click the interface and then select the cloud in the topology to connect the interface to. In this example FastEthernet 0/0 on R1 was selected and the link was joined to the cloud Internet_0.1-1

  1. Select an interface on the cloud to complete the connection. In this example, Ethernet0 on cloud Internet 0.1-1 was selected:

  1. Add another link between R2 and R1:

  1. Click the Add a Link button to stop adding links. The mouse cursor will change back to normal to indicate that you have stopped adding links:

  1. If not already done, click the Show/Hide interface labels button on the GNS3 Toolbar to display interface labels in your topology:

  1. You are now ready to power on your network devices. Click the Start/Resume button on the GNS3 Toolbar to start up your network devices:

  1. Click the Console connect to all devices button on the GNS3 Toolbar to open a connection to every device in the topology:

  1. A console connection is opened to each router in the topology:

Configure the GNS3 network:

  1. Login to the GNS3 Internet appliance:

        Username: gns3

        Password: gns3

username 'gns3', password 'gns3'
Run -b if you want to save your changes
box login: gns3
   ( '>')
  /) TC (\   Core is distributed with ABSOLUTELY NO WARRANTY.

[email protected]:~$

  1. Ping

        [email protected]:~$ ping

PING ( 56 data bytes
64 bytes from seq=0 ttl=127 time=14.306 ms
64 bytes from seq=1 ttl=127 time=13.987 ms
--- ping statistics ---
2 packets transmitted, 2 packets received, 0% packet loss
round-trip min/avg/max = 13.987/14.146/14.306 ms
[email protected]:~$

        Result The GNS3 Internet appliance is able to ping Internet devices.

  1. Configure the IP address of R1 (connected to the cloud):

R1# configure terminal
R1(config)# interface FastEthernet 0/0
R1(config-if)# ip address dhcp
R1(config-if)# no shutdown
R1(config-if)# end


        Result An IP address is allocated to the router by the Cloud DHCP server:

*Mar  1 00:02:14.619: %DHCP-6-ADDRESS_ASSIGN: Interface FastEthernet0/0 assigned DHCP address, mask, hostname R1


  1. Ensure that the router is configured to use the correct DNS server:

        R1# configure terminal

R1(config)# ip domain-lookup
R1(config)# ip name-server
R1(config)# end

Note By default the DHCP server on the Internet cloud will advertise itself as the DNS server and will reply to DNS queries.

  1. Ping

        R1# ping

Translating ""...domain server ( [OK]

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to, timeout is 2 seconds:
Success rate is 100 percent (5/5), round-trip min/avg/max = 12/21/32 ms

        Result Pings succeed.


If your pings don’t succeed, ensure that you have connectivity to your default gateway and ensure that the default gateway is configured for NAT to translate the address allocated to the GNS3 router. Also ensure that your firewalls are not blocking traffic.

  1. Configure IP addressing on the Internal GNS3 network:

        Configuration on the routers:

        R1        R1# configure terminal

R1(config)# interface FastEthernet 0/1
R1(config-if)# ip address
R1(config-if)# no shutdown
R1(config-if)# exit

R2R2# configure terminal
R2(config)# interface FastEthernet 0/0
R2(config-if)# ip address
R2(config-if)# no shutdown
R2(config-if)# exit

  1. Configure OSPF on R1 and R2 and advertise a default route:

R1R1(config)# router ospf 1
R1(config-router)# network area 0
R1(config-router)# default-information originate
R1(config-router)# end

R2R2(config)# router ospf 1
R2(config-router)# network area 0
R2(config-router)# end

        Result OSPF neighbor relationships are established:


        R1*Mar  1 00:10:30.275: %OSPF-5-ADJCHG: Process 1, Nbr on FastEthernet0/1 from LOADING to FULL, Loading Done

R2*Mar  1 00:10:30.307: %OSPF-5-ADJCHG: Process 1, Nbr on FastEthernet0/0 from LOADING to FULL, Loading Done


Note If the OSPF relationships are not formed, wait 30 seconds and check your configuration. Make sure you have configured IP addresses correctly, enabled the interfaces and cabled the GNS3 network correctly.

  1. Configure DNS settings on R2:

        R2# configure terminal

R2(config)# ip domain-lookup
R2(config)# ip name-server
R2(config)# end

  1. R2 will not be able to ping Internet devices until you configure NAT on R1. In this example, the Internet gateway does not support routing, so NAT will be configured on R1:

R1# configure terminal
R1(config)# interface FastEthernet 0/0
R1(config-if)# ip nat outside
R1(config-if)# interface FastEthernet 0/1
R1(config-if)# ip nat inside
R1(config)# ip nat inside source list 1 interface FastEthernet 0/0 overload
R1(config)# access-list 1 permit
R1(config)# end
R1# wr

  1. Test R2 connectivity to the Internet:

        R2# ping

Translating ""...domain server ( [OK]

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to, timeout is 2 seconds:
Success rate is 80 percent (4/5), round-trip min/avg/max = 36/40/44 ms
R2# wr

        Result R2 is able to ping devices on the Internet.

  1. Congratulations! You have configured Internet connectivity from GNS3 VM devices.