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What is   DNS Amplification Attack   ? Before we understand the DNS Amplification Attack, lets learn about DDoS first. Distributed denial-of-service Attack (DDoS), is a cyber threat looming large on Organizations. It adversely affects the online productivity of individuals too. Anyone who relies on their Internet presence to generate revenue can be a target. The Security tangent comes in question here. First, let us understand what DoS attack is. A denial of service (DoS) attack is a malicious attempt to make a server or a network resource unavailable to users. This is usually performed by interrupting or suspending the services of a host connected to the Internet. Distributed DoS (DDoS) attacks are DoS attacks launched from multiple hosts simultaneously. The flood of incoming messages to the target system forces it to shut down or choke bandwidth. Hence, denying service to the legitimate users. The domain name system (DNS) is one of the most critical service that

Slave/Secondary   DNS Server (Read Only DNS Server) How AXFR & IXFR Works in DNS for Zone Transfer   ? The term slave simply indicates that a name server will obtain the zone records using zone transfer operations but will answer authoritatively for the zone for as long as it has valid zone data (defined by the expiry field of the zone’s SOA RR). The term slave in no sense implies priority of access. As previously described, slave servers will be accessed, in general, just as frequently as any master name server. Slave servers may also transfer their zone files to other slave servers.   The Zone Transfer between Master Server and Secondary Server What is AXFR ? AXFR Transfer : The DNS polling process is accomplished by the slave name server sending a query to the zone master requesting the SOA RR. If the SOA RR’s serial number is greater than the current one maintained by the slave name server, a full zone transfer (AXFR) is requested by the slave DNS.