I have a Cisco 2811 router that I use as a gateway for a local /24 LAN. We are shutting down another office and moving the assets and functionality to this office so we are going to need more space than the /24. I am going to just take the second Fe interface on that router and create another /24 subnet on it. We will have all servers and printers on the first LAN (192.168.100.0/24) and the all the users and their IP phones on the second LAN (192.168.101.0/24).
I know that since they are on the same router it will automatically see and create the route between the two networks but I would like some confirmation. Will the computers on the user LAN automatically be able to hit the domain controllers on the server LAN for logging into the domain and DNS? I don't really need any kind of filtering between the two subnets right now so I wasn't going to do an access-list unless necessary.