help me explain

[Cuttler, Brian R (HEALTH)]

Please help me to explain to another admin at my site, or tell me that I'm wrong and what I need to do in this case.

We are in process of restructuring our network in one of our buildings. There are good aspects of this, better redundancy, dual paths from each switch to the primary router on site, etc, and there are parts of this that are not strictly necessary and will in some ways make more work.

We are dividing the 6 floor building from a /21 network and creating a new /24 on each floor, we are for the first time in this building enabling DDNS. (yes, we have a net of two /24 networks free when we are done)

The positives are that the printers will now provide an identifier (string matching their inventory tag) to DHCP then to DNS, and we will be able to create DNS short names pointing to their FQDN, so we don't need to remap anything from either the print servers or directly mapped printers - well, for printers mapped by ID rather than IP.

I know from when we did something similar at the first building which is using a /22 network for the entire building (regardless of floor) that I can use a single subnet name, and can have one named Forward table but needed 4 Reverse tables. No problem there. (Is there a better/easier way)?

The issue in question is that while it is only a /24 on each floor and I can use one Forward and one Reverse table FQDN (I believe) needs to be unique by floor. IE if a printer moves I don't need to lock it down, never need to enter it in DHCP, but do need to change its CNAME to point to the new FQDN since each floor requires a different subnet name.

Am I correct in my understanding, or is there a way to maintain unique address ranges by floor but use a single subnet name for the entire building?

Many thanks,
Brian