GNS3

The content in this post is intended for educational and informational purposes only. All software rights belong to their respective owners. I’ve read quite a few tutorials on Netmiko with GNS3, but none of them show you how to directly utilize the console connection as the management interface for Cisco devices. In addition to the CiscoIosSSH driver, Kirk Byers also implemented the CiscoIosTelnet driver for establishing a connection to a Cisco device. This is perfect for GNS3 because the default console connection is essentially a Telnet connection without authentication. ...

The content in this post is intended for educational and informational purposes only. All software rights belong to their respective owners. Cisco recently made the IOS on Linux (IOL) images available through the Cisco Modeling Labs (CML) Free Tier . IOL is an implementation of Cisco IOS-XE that operates as an executable binary on Linux. This post will guide you through the process of adding Cisco IOL devices using GNS3 on macOS. ...

Most GNS3 users are familiar with VPCS . It’s the go-to device for simulating a simple endpoint node in our network labs. VPCS is suitable for the basics, but Docker supplies a selection of more feature-rich endpoint types. This post provides an example using Alpine Linux . Prerequisites GNS3 with macOS on Apple Silicon GNS3 client Steps Open your favorite terminal emulator. Download the latest alpine Docker image from Docker Hub . ...

As of the date of this post, GNS3 does not provide a native client for macOS on Apple Silicon. This post aims to address that issue. While this post serves as a companion to GNS3 with macOS on Apple Silicon , the GNS3 client described here will also function with other types of remote GNS3 servers. Prerequisites Mac computer with Apple silicon macOS Sequoia Git Steps Open your favorite terminal emulator. We will be working from the command line for the majority of the following steps. ...

The content in this post is intended for educational and informational purposes only. All software rights belong to their respective owners. Dynamips may seem to be a bygone technology for the present day, but it’s still a great solution for learning routing concepts on emulated Cisco router platforms. Want to kick it old school with the Cisco 7200 Series Router? ...

Ghostty is my primary terminal emulator for macOS, but I prefer to use a separate terminal emulator for GNS3 console (telnet) connections. After some research, I decided on Alacritty . It’s lightweight and supports the command-line options we need for GNS3. There are several ways to install Alacritty and Telnet, but I use MacPorts in this post. Steps Open your favorite terminal emulator (besides Alacritty 😉). Update the local ports tree with the global MacPorts ports repository. ...

The content in this post is intended for educational and informational purposes only. All software rights belong to their respective owners. The Cisco IOSv and IOSv L2 devices could be considered the standard for learning Cisco routing and switching in the confines of a virtual network environment. They’re light in resource usage and contain a vast feature set. Prerequisites Cisco Modeling Labs subscription GNS3 with macOS on Apple Silicon macOS Point your web browser to the CML Software Download page. ...

Before we work our way through the steps, I will start by pointing out GNS3 server has the following constraints when running on Apple Silicon: Lack of Linux KVM for x86_64 virtualized guests Slight performance penalty with emulated x86_64 Linux binaries (Rosetta ) The following are my results after testing a number of different Cisco device types: Device Working? Information IOL ✅ - IOL L2 ✅ - IOSv ✅ - IOSv L2 ✅ - ASAv ❌ Requires SSSE3 CPU instructions for cryptographic operations Catalyst 8000V ❌ Requires vmx or svm CPU flag for Linux KVM Nexus 9000v ❌ Requires vmx or svm CPU flag for Linux KVM As you can see, we’re primarily limited to Cisco (IOL , IOSv , Dynamips ) images, VPCS, and Docker containers. The upside is that we’re rarely CPU-bound running labs on Apple Silicon. The amount of system memory in the Mac is usually the limiting factor. And let’s face it: connecting to a dedicated x86_64 GNS3 compute server with ample CPU cores and RAM is the ideal solution for running large labs. ...

After opening the GNS3 client and starting nodes, we primarily access the remote virtual devices with a console connection. This console connection is either Telnet, VNC, or SPICE. A console connection covers our requirement for physical access to virtual devices, but today, most administrative tasks are carried out with a link to the network management interface . I define the GNS3 server as remote if the gns3server process is not running on the host operating system. I consider the GNS3 VM remote because the gns3server process runs on a guest operating system (Ubuntu). ...

This post is a companion to the previous GNS3 with Microsoft Azure post. For many of us, an asymmetrical Internet connection usually equates to a much slower upload than download speed. Specifically, in our case, this results in a time-consuming process of uploading GNS3 image files to our remote gns3server VM instance. What if we need to recreate the disk attached to our gns3server VM instance? Modify the type (i.e., HDD to SSD) or decrease the size of the disk, which again would require us to recreate the disk? What if we need to spin up multiple gns3server VM instances for training purposes? Each situation may require a good amount of unnecessary (re)uploading. ...