I am a programmer trying to get Rancher (Kubernetes) setup. Rancher's config file has a setting called service_cluster_ip_range.

It expects a CIDR notated subnet.

My network team gave me a "24" subnet. They told me that the IP address range I can use is 10.70.9.11 - 10.70.9.254.

As I understand things, when you say 10.70.9.0/24 you are referring to 10.70.9.1 - 10.70.9.254.

When I asked my network team if I could have addresses 1 - 10 as well I was told that they were reserved for network gear (and that the network would fail if they gave me those addresses).

So, my question is does CIDR deal with exclusions like this? Can you say something like 10.70.9.0/24 Exluding (.1 through .10) or something like that?

Or will have have to give up a bunch of addresses and do 10.80.9.128/25?