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