I recently did a post on now I’m going to show you how to setup a layer 3 switch with in GNS3. What is the difference? Well there are many but this is not that kind of article. For starters show VLAN will give you an ambiguous command off the bat on a layer 3 switch.
Add Cisco IOU switch and rename to iSW1, connect e0/0 to iR1’s e0/0. Before Cisco IOU, there was Dynamips (GNS 3 is a GUI Dynmaips, nothing more) and Cisco Packet Tracer. In the last 10 to 15 years, we have seen these readily free applications which either try to emulate or simulate the real. Sep 22, 2013 - GNS3 can emulate only routers (and run their IOS images). You can try Cisco Packet Tracer for switches, but keep in mind that it is a simulator.
But basically a layer 3 or core switch can route between VLAN’s whether they or private or not,etc. The layer 2 switch i talked about in my other article uses IOS on Unix IOU. This method for the layer 3 switch basically uses a router image with a switching module. And yes you can do the same thing on real equipment!
First of all you are going to need GNS3 and some router images. If you need these you can read my article on or you can go directly to the.
Go into the preferences Edit Preferences and select the IOS routers under Dynamips. You can select one of your previously decompressed images in your GNS3 images folder (it’s ok if it’s already used for another router) I’m using the 3725 image. In this step make sure you select This is an EtherSwitch router and click Next. In the next step you can change the RAM but 127mb is fine. Then GNS3 will automatically select the switching module for you! As shown here. Click next.
In the next few dialogues it’s just like adding any other image. Set the IDLE PC value,etc then the EtherSwitch should appear in your list:. Now you should have a working layer 3 switch with about 16 ports! I hope this helps! Remember you can use any router image all though I have only used the 3725 with this example. This article was viewed (31068) times!