Usually no. There are generally two types of floods against DNS infrastructure: - Flood of "valid" requests, to a large number of open DNS recursors. To avoid

Usually no. There are generally two types of floods against DNS infrastructure: - Flood of "valid" requests, to a large number of open DNS recursors. To avoid caching they usually contain random prefix. Flood against large number of open DNS recursors basically causes the recursors to not work, and many authoritative servers to be overwhelmed. - Flood directly against authoritative servers, to fill the network or use up all the CPU. Traditional reflections aren't that popular any more.