In this article, we will examine how to set up and use GNS3 VM 2.2 (2.2.34) in order to use Cisco IOU devices more stable and performance or to create all your projects on a single machine in the openSUSE Leap 15 (15.4) distribution.
How to Set Up GNS3 VM (Virtual Machine) 2.2.34 on openSUSE Leap 15.4
GNS3 is a free advanced networking software often used for Cisco exams. You can create various network designs by emulating Cisco’s IOS Router network devices. You can use not only Cisco’s devices but also network devices from other 3rd party manufacturers in the virtual environment.
Normally, IOS devices are sufficient for entry-level network designs, but when you need to use a Firewall device such as Cisco ASA in your more advanced projects, you may need to use the GNS3 server software.
For your more advanced Switching projects, you can use all the features of a Layer 2 Switch only with IOU images. We recommend configuring the GNS3 VM on a powerful PC so that you can run IOU images more efficiently.
You can use the GNS3 virtual machine in the openSUSE Linux distribution, but you must have virtualization software installed on your system. Since VMware Workstation is the most widely used software, we will use this software in our article. Before starting the installation steps, install the necessary software on your system by following the guides below.
According to the virtualization software installed on your system on the Download GNS3 VM website, click the Download button in the VMware Workstation and Fusion title and download the zip file to your computer.
After downloading the GNS3 VM.zip file, navigate to its location and execute the “unzip GNS3.VM.VMware.Workstation.2.2.34.zip” command in the terminal to extract the archived file to the folder.
After extracting the OVA file to the folder, open VMware Workstation 16 Pro and click File / Open from the tool menu.
When the Open Virtual Machines window opens, select the OVA file and open it.
To import the GNS3 virtual machine on Workstation, leave the relevant location at the default and click the Import button.
Wait while the GNS3 virtual server is being imported into the Workstation program.
Before running the GNS3 server, upgrade the hardware version and adjust the virtual processor and memory settings depending on the performance of your host PC. Then click Start up this guest operating system to start the virtual server.
After the GNS3 VM starts, you can see the IP address that the Workstation software automatically gets from the DHCP service. Use the ping command in the terminal to test the connection between your host computer and your virtual server.
When the GNS3 VM is ready, open the GNS3 software and click Help / Setup Wizard from the tool menu. Select Run appliances in a virtual machine in the setup wizard and click Next.
In the GNS3 local server connection settings, select the Host Binding IP address according to the virtual server IP block and continue.
After a successful connection to GNS3 Server, click Next.
After choosing one of the software you have imported the GNS3 VM.ova file, configure the vCPU setting to 2 and the virtual memory size to 2 GB.
After configuring the server type, check the settings in the summary window and close the wizard.
How to Add Cisco Router IOS
After making the GNS3 VM connection, you can add a new IOS Router and add the network device you added to the workspace and create network topologies.
Click Edit / Preferences from the tool menu to open the simulator program’s preferences to open the Cisco IOS add wizard.
Select Dynamips / IOS routers from the settings on the left panel and click the New button to open the IOS wizard. In the window that opens, select Run this IOS router on the GNS3 VM to add the router to the virtual server and click Next.
To add an IOS image you downloaded to your computer, click the Browse button and select the file.
Click Yes to decompress the IOS image and wait for it to be uploaded to the server.
Edit the name and platform of the new IOS Router and click Next.
Configure the virtual memory size according to the RAM capacity for the Router to work efficiently on your computer and click Next.
You can choose the default network adapters from the empty slots for each Router you will add to your project. For example, only the FastEthernet interface is installed by default, but you can add GigabitEthernet or Serial Interface additionally.
To prevent IOS images from using 100% of your computer’s processor, you need to set an Idle-PC value. Click Idle-PC Finder to find a suitable value for the IOS device you added.
To check whether the IOS image was added to the virtual server, you can check the Server value in the device information section.
How to Create a New Project
After installing GNS3 VM on openSUSE and adding a new IOS device, you can now make network designs and observe how computers in the network environment communicate.
You can use CTRL + N keys or click the project icon from the tool menu to start a new project in GNS3 software.
Expand the Routers category and drag and drop two c7200 devices into the workspace.
Activate the cabling option from the left panel, and then connect one end of the network cable to the FastEthernet0/0 port of R1 and the other end to R2.
To run all the network devices you have added to the GNS3 program, click the green arrow in the tool menu and click Yes in the window that opens.
Execute the commands below in the CLI prompt to assign and configure IP addresses to the FastEthernet interfaces of the R1 and R2 devices. Finally, use the ping command to test the network connection between the two Routers.
R1# conf t
R1(config)# interface fastethernet 0/0
R1(config-if)# ip address 192.168.1.1 255.255.255.0
R1(config-if)# no shutdown
R2# conf t
R2(config)# interface fastethernet 0/0
R2(config-if)# ip address 192.168.1.2 255.255.255.0
R2(config-if)# no shutdown
How to Disable GNS3 VM
If you want to disconnect the GNS3 from the GNS3 server, you must disable the GNS3 VM in the program’s preferences.
After opening Edit / Preferences from the program’s menu, select the GNS3 VM from the left panel and then uncheck the Enable the GNS3 VM option and click OK.
After disabling GNS3 VM, you need to run IOS devices on localhost. To do this, open Help / Setup Wizard and select Run appliances on my local computer from the server configuration options and click Next.
Change the Host Binding value in the local server configuration to localhost this time and continue.
After the local GNS3 server connection is successfully established, check the settings in the summary window and close the wizard.
When you make the local server settings, you need to delete the c7200 Router IOS that you added to the GNS3 server. If you see that the Server setting of the c7200 device is VM in the IOS Routers section, select the device and click the Delete button.
When you delete the device on the server, open the template wizard again and this time select Run this IOS router on my local computer and click Next.
You can check that the Server setting of the IOS device you added is localhost. In this way, you can run your network devices on the local server without the need for a GNS3 VM.
How to Delete the GNS3 Virtual Machine
When you no longer want to use a GNS3 Server on your openSUSE computer, we recommend deactivating it and then completely deleting it from the Workstation program.
Open VMware Workstation 16 and select the virtual computer you want to delete from the Library panel, then right-click on it and click Manage / Delete from Disk and confirm the complete deletion from your system disk in the question window that opens.
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