#366 logical block assignment

[Don Badrak]

Hi. Wonderful tool! This is making things so much easier.

One thing we do here is create a large subnet block (say, a /24) and use it for smaller groups of sites, even point to point links, like a /31. Or, sometimes we allocate a small block like a /29 within a subnet (a /24, for example) to be used for specific purposes, like permitting access through a firewall. When creating such a child subnet of /29, IPAM doesn't permit the use of the network+0 and network+broadcast address for assignment.

We would like to see an option where you can create a subnet block that's not actually used as a subnet but is more a logical grouping of hosts on a powers-of-two boundary for ease of administration (firewall rules, Cisco ACLs) and have access to the 0 and broadcast IP for assignment (that is, all possible addresses)

Thanks.

Don

[Markus]

We use this hierarchical concept as well, e.g.:
10.10.20.0 / 24 containing several /29er transit subnets. You can define these subnets as child subnets of
* 10.10.20.0/24
* 10.10.20.0 / 29
* 10.10.20.8 / 29
* and so on,

so you are already able to use the first "net address" (10.10.20.0/24) as the first underlying subnet with the /29 netmask... maybe I haven't understand the problem?

[Don Badrak]

Right, that works, but I want to assign a host to that network address. So, if I had a block 10.10.20.32/27 that I logically allocated to a group of hosts that needed special access, I can set up firewall rules more simply with the /29 mask, but the subnet is really a /24, and I need to assign a host IP to that 10.10.20.32 address. As it is now, I can't assign 10.10.20.32 or 10.10.20.63 if I set up 10.10.20.32/27. My current hack is to also define 10.10.20.32/32 (and 10.10.20.63/32), though that seems very ugly.