Revert "use fetchAll() in getAllIPv4Allocations()"

This reverts commit 4d625ebfe9da0d46ebce89f4df533f001b31261b.
Revert "Revert "use fetchAll() in getAllIPv4Allocations()""

This reverts commit 8421f934b7bc8cfb523d843dd138e77257cd2f00.