We are moving from several 1U servers colo'ed out across several data centers to a full rack in a nearby data center for both physical access reasons, as well as having space for expansion. We also will probably sell off a bit of colo space here and there. Also, the full rack price is actually right at the cost we're paying for our disparate 1U colo, so it makes economic sense.
We have a 1GB drop and a full /24 provided along with the rack.
Our assumption is that we'll need a layer 3 switch to divide the /24 into subnets not only for our selves, but to keep any colocation we provide to anyone else completely separate.
Can I use a 48 port layer 2 switch for our own servers, coming up into a 24 port layer 3 that splits the subnets from there? As I understand it, a layer 2 switch would allow you to separate various servers into VLANS, but they would all use a singular gateway. Layer 3 would allow you to divide them into "true" subnets with their own gateways. Am I on the right track here, or the wrong one?