candidateSubnets

Up to 16 candidate prefixes that can be used to restrict the allocation of cloudRouterIpAddress and customerRouterIpAddress for this attachment. All prefixes must be within link-local address space (169.254.0.0/16) and must be /29 or shorter (/28, /27, etc). Google will attempt to select an unused /29 from the supplied candidate prefix(es). The request will fail if all possible /29s are in use on Google's edge. If not supplied, Google will randomly select an unused /29 from all of link-local space.