I want to setup a network with two domains, one is a .com the other is a .net I have one router. Would it be better to have the networks divided at the router or use a switch after the router, I do not want traffic from the .net side to enter the .com side
I would recommend using both a router and a switch. Create VLANs for the gear on the .net side and a VLAN for the .com side of the network. Configure a port on the switch to be a VLAN trunk (ISL or 802.1q) and trunk the traffic to the 100Mb interface on the router. Very common "router-on-a-stick" configuration. Traffic can be controlled to prevent the .net and .com side from communicating by using ACLs on the router. The only real caveat is that your router needs a 100Mb interface.
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...