Most of us use our Google Homes, smartwatches, security cameras, and other handy gadgets on a daily basis. The Internet has undoubtedly made our lives ten times easier than before. However, the thing that makes these devices so convenient and easy to use is the same thing that makes them most vulnerable to malicious cyberattacks.

A reverse proxy is a server that sits in front of the webserver, intercepts the request, and either respond to the client with a response from its cache or forward the request to the origin server. A reverse proxy is used to protect the web servers from DDoS attacks, distribute load amongst multiple servers, and utilize its cache to serve static contents without sending requests to the origin server. No client will communicate directly with the server, and the server's IP address will not be revealed to the public.

A denial of service (DoS) attack is an explicit attempt made by an attacker to make victim's Internet resources unavailable to its intended audiences. The DoS attack is usually carried out by one machine connected to the Internet by exploiting known UDP and TCP vulnerabilities.

Wordpress is one of the most popular CMS platform available today with over 75 million websites powered by it. The popularity comes with risks as vulnerabilities and weakness of such platform will be shared amongst hackers and script kiddies, and automated bots will be searching for websites built on Wordpress platform.

Given the fact that a DDoS attack can bring down any computer system in spite of the advanced hardware setup, it is essential to do some periodic checks in order to detect the possibility of a DDoS attack. Here are some essential ways to prevent and mitigate a DDoS attack.

One of our sister website hosted on cloud server was recently hit by a 9Mbps DDoS, and the apache web server ran out of memory and crashed. The attack lasted more than 2-months with no known reason. We've taken a number of mitigation steps including installation of mod_security with mod_evasive, APF, BFD, DDoS Deflate and Rootkit and Traffic Control, but none came to rescue. Use of Linux provided WAF will mitigate the DDoS to the extent where CPU, Memory and Bandwidth are allowed; and in our case a single CentOS server with 4GB RAM wasn't sufficient to mitigate DDoS.

The two methods described below are extracted from the lartc howto. It is included here to provide a complete reference. For latest updates, please view source document.

Being a web host, your servers are constantly being attacked by hackers by denial-of-service (DoS) and other brute force attacks. There is no foolproof method to stop 100% of all attacks, but there are ways to protect your servers by applying firewall rules, and detecting and banning attacking IPs.

DoS attack, denial-of-service attack, is an explicit attempt to make a computer resource unavailable by either injecting a computer virus or flooding the network with useless traffic. In simple words, it is similar to thousands of people trying to enter a room from a single entrance, ultimately causing havoc. This not only disturbs the normal operations of the network but also results in poor performance and system breakdown due to overwhelming requests. A large-scale DDoS attack (ranges up to 400 GBps) can affect the internet connectivity of an entire geographical region. There are two types of DoS attacks: computer attack and network attack. Common forms of denial of services attacks are: