Option to exclude .0 and .255 addresses automatically from IPv4 subnets larger than /24
This is a feature request.
Having encountered thrice recently (twice using Kea and once using ISC DHCP) a scenario where a large IPv4 subnet had its pools defined as many small ranges, specifically to avoid the .1 and .255 addresses, I wondered if it might be a good idea to have a configuration option to make this happen automatically.
The reason for excluding these addresses is that some broken clients don't handle them well, even though they should, if the netmask is shorter than 255.255.255.0 - thus leaving operators in a quandary - particularly in environments where they either don't have control over which clients are allowed addresses on their network, or where they have known broken equipment that cannot be assigned fixed addresses or easily upgraded/replaced.
There is a similar feature request opened for ISC DHCP: dhcp#20 (closed)
The workarounds for ISC DHCP and for Kea are different however - it's not possible (currently) in ISC Kea to reserve an address without giving it host ID - either MAC address or client-id - which means creating some sort of 'fake ID' scheme to operate. But it's doable, but for the scenario where it's needed (i.e with a very large number of small subnets) either has to be automated, or is significantly tiresome to set up manually.
Adding an option would therefore make configuration much simpler for those who need this for their subnet definitions.