DNS-flood attack

DNS-flood attack is a Distributed Denial of Service (DDoS) attack means. The attacker sends a large number of query packets to the Domain Name Server (DNS) within a short time. Therefore, the server has to respond to all the query requests. As a result, the Domain Name Server cannot provide services for legal users.

The Firewall can detect DNS-flood attack based on the querying rate of the DNS packets. The querying rate of the DNS packets is restricted. DNS packets that exceed the specified rate are directly discarded.

Please share how can we configure to protect this type of attack.