Currently, NeutronDbPluginV2._validate_allocation_pools() does some very basic checking to be sure the specified subnet is valid. One thing that's missing is checking for a CIDR of /32. A subnet with one IP address in it is unusable as the sole IP address will be allocated to the gateway, and thus no IPs are left over to be allocated to VMs. The fix for this is simple. In NeutronDbPluginV2._validate_allocation_pools(), we'd check for start_ip == end_ip and raise an exception if that's true. I've opened lauchpad bug report 1271311 (https://bugs.launchpad.net/neutron/+bug/1271311) for this, but wanted to start a discussion here to see if others find this enhancement to be a valuable addition. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.openstack.org/pipermail/openstack-dev/attachments/20140121/e9816748/attachment.html>