[openstack-dev] [Neutron][IPAM] Uniqueness of subnets within a tenant

Carl Baldwin carl at ecbaldwin.net
Wed Mar 11 16:46:27 UTC 2015


On Tue, Mar 10, 2015 at 12:06 PM, Ryan Moats <rmoats at us.ibm.com> wrote:
> While I'd personally like to see this be restricted (Carl's position), I
> know
> of at least one existence proof where management applications are doing
> precisely what Gabriel is suggesting - reusing the same address range to
> minimize the configuration differences.

Okay, I see the problem.  I'm not particularly thrilled about this
situation but I see the problem.  Can we deprecate this mis-feature?
Is there hope that we can stop this madness some day?  :)

Regardless, it sounds like we need to support this for at least some
time in the future.  So, here is what I propose:

When talking with external IPAM to get a subnet, Neutron will pass
both the cidr as the primary identifier and the subnet_id as an
alternate identifier.  External systems that do not allow overlap can
simply ignore the alternate identifier.  Salvatore, I'm mostly
speaking to you when I ask this but would welcome others' opinions
too.

Carl



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