Author: Boyan Peychev

Boyan Peychev is Founder and CEO of ClouDNS.

10 most used Nslookup commands

Boyan Peychev / / DNS

What is Nslookup?

First lets clarify what is Nslookup – it is a powerful network administration command-line tool, available for many of the popular computer operating systems for querying Domain Name System (DNS) to obtain domain names or IP addresses, mapping or for any other specific DNS Records.

Need more details what is nslookup? Check the nslookup page on wikipedia.

DNS, records, nslookup

Here are the 10 most used command lines with nslookup that will help you to understand better your domain’s management:

Continue reading “10 most used Nslookup commands”

DDoS amplification attacks by Memcached

Boyan Peychev / / DDoS
DDoS amplification attack
DDoS amplification attack

What is DDoS amplification attack?

These attacks usually use the UDP protocol. It is a simple connectionless communication model with a minimum of protocol mechanism. This means that one of the sides in the communication can send large amount to the other without restrictions. Without any confirmation and it doesn’t matter if the second side receive the data.

Due to the way the UDP protocol works, cyber-criminals use it to generate DDoS amplification attacks. The attacker sends a small UDP request with a spoofed IP address of the victim to public services.

The UDP protocol doesn’t require a connection verification between the parties. This is why the public services reply with the requested data to the IP address of the victim. As bigger is the data returned by exploited public service, bigger is the DDoS amplification factor.

In the past few years, hackers have exploited many public DNS resolvers and NTP servers to generate massive DDoS attacks against popular websites and services. Continue reading “DDoS amplification attacks by Memcached”