minimize attack with iptables

You can minimized DDOS attack with some basic actions with the iptables.
Syn-flood protection:

In this attack system is floods with a series of SYN packets. Each packets causes system to issue a SYN-ACK responses. Then system waits for ACK that follows the SYN+ACK (3 way handshake). Since attack never sends back ACK again entire system resources get fulled aka backlog queue. Once the queue is full system will ignored incoming request from legitimate users for services (http/mail etc). Hence it is necessary to stop this attack with iptables.

Force SYN packets check:
Make sure NEW incoming tcp connections are SYN packets; otherwise we need to drop them:

iptables -A INPUT -p tcp ! --syn -m state --state NEW -j DROP

Force Fragments packets check
Packets with incoming fragments drop them. This attack result into Linux server panic such data loss.

iptables -A INPUT -f -j DROP

XMAS packets
Incoming malformed XMAS packets drop them:

iptables -A INPUT -p tcp --tcp-flags ALL ALL -j DROP

Drop all NULL packets
Incoming malformed NULL packets:

iptables -A INPIT -p tcp --tcp-flags ALL NONE -j DROP

See the book OpenCart 1.4 Template Design Cookbook.
See the book Joomla Mobile Development Beginners Guide

List of my works:

Technical Support:

If you still face the technical problem, please get support of our highly skilled technical team: garazlab.com.


Wordpress Plugins:

1. Real-Time Health Data from Every Where:WP plugin to display real-time health data & increase sale by promoting user specific products according to health information: garazlab.com.
2. Woocommerce Stock Notification Builder:Sends desktop, mobile & email notifications with full customization.Build your own product notification system with it: garazlab.com.

Opencart Extensions:

1. Product Based Quantity Wise Shipping: Find it here.
2. OpenSSLCOMMERZ: integrate SSLCOMMERZ with opencart: Find it here.
3. Fine Search v.1.0 - Improves Opencart search feature to find relevant: Find it here.
4. Opensweetcaptcha - An easy way to generate attractive captcha for your system!: Find it here.
5. Custom Field Product - add unlimited custom fields to the product form: Find it here.
6. Formcaptcha - add captcha on the register page: Find it here.

My Books:

1. OpenCart 1.4 Template Design Cookbook.
2. Joomla Mobile Development Beginners Guide