How to make a router function as a switch in GNS3

GNS3 is open-source software that helps in emulating networks using the Cisco Internetwork Operating Systems (IOS). GNS3 enables you to run a Cisco IOS in a virtual environment and serves as a graphical user interface to Dynamics. For some articles I have written on GNS3, please see the following guides “Error–Failed to open a session for the virtual machine GNS3 VM, how to make a router function as a switch in GNS3 and Graphical Network Simulator: How to connect GNS3 to the internet on Windows. When it comes to network simulators and emulators, everyone has their favorite. In this article, I will be discussing the Graphical Network Simulator (GNS3).

A Router provides routing capabilities (intent-based networking for the WAN, LAN, and cloudRouters connect computers and other devices to the Internet). In this guide, I will be demonstrating how to may a router act as a layer two device on the network.

In order to achieve this in GNS3, follow the following steps below: Drag your router into the topology
– Right click on it and choose “configure
– Go over to the “slots” tab
– Leave the “slot 0” the way it is
– Make a “slot 1” entry for “NM-16ESW”, apply and save your changes
– Change the symbol on it to look like a switch if you want
– Enter the “no ip route” command in global config mode so it doesn’t act like a router

Switch_Router(config)#no ip routing
Switch_Router(config)#do copy run start

Note the following deviations from a normal switch config.
Switch# show vlan-switch
Switch# vlan database

I hope you found this blog post helpful. If you have any questions, please let me know in the comment session.

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