What is the canonical way to simulate Ethernet subnets?

[xlearnsy]

I am describing the simple case where there are multiple nodes in a subnet (say 192.168.1.0/24), connected to a gateway switch/router (192.168.1.1), which is then connected with the gateway routers of 192.168.2.*, 192.168.3.* and so on.

From what I have read, there seems to be no particular easy way of setting up this. 

In the examples it seems each node-router pair is treated as a separate subnet using point to point link, so the router node has a lot of netdevices with different IPs, which is not what I want. 

There is also a csma model that can act like a network switch but the whole CSMA/CD thing does not feel relevant in today's Ethernet.

Am I missing something in here?