How to Install Graphical Network Simulator (GNS3)

GNS3 is a network software emulator used to prepare for Cisco CCNA and CCNP exams, simulate Cisco IOS, or graphically simulate different UTM devices. In addition to being free of charge, unlike Cisco Packet Tracer, it is one of the main reasons for the preference that both Cisco and other manufacturers simulate both real and virtual hardware instead of just Cisco devices.

Step 1: You can download the GNS3 program after registering from the website https://www.gns3.com/.

Step 2: We start the installation of the GNS3 program that you downloaded according to the OS you used.

Step 3: We accept the license agreement with “I Agree” on the screen and proceed to the screen in the Setup R3 picture.

Step 4: In this screen, you can select additional applications that you may need with GNS3. Make sure that your computer can log on to the internet as it will need an internet connection for every additional application you choose.

Step 5: You can see on the screen that Wireshark, which we preferred from the additional features during the installation process, has downloaded from the internet.

After the installation process is completed, when you run the GNS3 program, you will see the first Setup Wizard screen. There are 3 options on this screen. Let's briefly talk about these;

1) Run Modern IOS: You can use this option to run the Cisco IOS and Applications and other non-Cisco applications. However, in this case, you must install GNS3 VM on a virtualization platform like a VMware Workstation. Again, GNS3 VM can use for free.

2) Run only legacy IOS my computer: In this option, it is the platform from your past that you can run C7200 equal or less on your computer. It is kind of working as a Cisco Packet Tracer.

3) Run everything on a remote server: In this option, it is to run GNS3 VM on a server at a remote location instead of using computer resources. However, since we have not installed the GNS3 VM on the remote server yet, we will not use the Setup Wizard.

After this stage, we can install GNS3. The indispensable requirements for this are as follows.

Minimum 2 GB Ram varies according to your recommended needs.
Minimum 1 CPU varies according to your recommended need.
Minimum disk space 150 GB

According to the virtualization platform on the remote server, we start the process by downloading the VMware ESXI from https://www.gns3.com/software/download-vm.

The extension of the file we downloaded. We understand that it is OVA, we will do this file "Open Virtualization Format" Deploy. For this, we connect to Vcenter or ESXI host and open the relevant interface.

We proceed to the next step by selecting Create / Register VM on our ESXi host.

After selecting the option "Deploy a virtual machine from an OVF or OVA file", of course, we complete our next steps by clicking NEXT.

Finally, we expect our OVA file to finish importing with the "Finish" process. At the end of the process, GNS3 VM will be installed on ESXI, but since the KVM support available status is False, we need to make some more settings, so we turn the GNS3 VM off and proceed to the next step.

We open the edit on GNS3 VM and select the "Expose hardware-assisted virtualization to the guest OS" option in the "Hardware virtualization" option under the "CPU" option and save and exit.

Then, we come to the Networking section on the Host and start the process of creating an "Add a group" network to prevent the VMWARE Security measures.

In the new screen, we assign a name to the name field as GNS3 or you can give a name depending on your preference. We create the new port group with “Add” by marking all of the Promiscuous modes, Mac address changes, forged transmits options in the Security field as “Accept”.

To return to the GNS3 VM and make a revision with the edit option, we select and save the port group network that we created GNS3 instead of the VM Network in the "Network Adapter 1" option. Now we can power up the GNS3 VM and turn it on.

When the GNS3 VM is opened, an information screen will meet you. This screen contains information about version information, IP address and where image files are kept. If you want, you can view other settings after clicking the “OK” option and make the necessary changes depending on your request. For example, you can change the IP address, update or give username and password for Remote GNS connections.

References

• GNS3
• SYSNETTECH Solutions

Read Also:

• https://slides.com/michealsean/ascii-tables
• https://slides.com/michealsean/igmp-protocol