Feature request: allow allocation of network/broadcast address if IPPool/ExternalIPPool is defined by CIDR

[ghormoon]

In some cases (eg in some server hosting providers), you're given "subnets", eg /29, which are in reality just a range of IPs in a bigger subnet, so the first and last address are actually not a network/broadcast address.
The same applied if you're assigning single addresses to the pool with /32. - they get ignored (thanks for improving documentation in #6183)

it is actually currently possible to replace eg.

- cidr: 10.0.0.42/32

with

- start: 10.0.0.42
  end: 10.0.0.42

but it would be much nicer to just flip a flag on the (External)IPPool that would make it allocate the first/last cidr addresses (default would need to be false, to keep backwards compatibility).
It would make it much more readeable and allow me to use same lists of addresses in ansible for both antrea and metallb (which doesn't ignore them in CIDR like this) without having to transform the cidr by some heavy magic into the start+end format

[tnqn]

@ghormoon thank you for the proposal. It makes sense to me. I will see if this can be included in the next release.

[antoninbas]

A similar MetalLB configuration flag that @ghormoon mentioned to us on Slack: https://metallb.universe.tf/configuration/_advanced_ipaddresspool_configuration/#handling-buggy-networks

[ghormoon]

just note that metallb has the oposite behaviour. it doesn't ignore them, only ignores .0 and .255 if he flag is on (and not even the other ip's if the subnet is eg /29 and doesn't start at x.x.x.0/29)
but for backwards compatibility we need to keep the default to ignore