Shorewall is an open source tool firewall to manage Linux built upon netfilter (iptables,ipchains) systems. It’s an abstraction layer to manage netfilter rules, easier than iptables based in configuration files. In this post I’ll show the basic implementation to begin
Mitigating a SYN Flood Attack
Before speak about syn flood and some possible mitigation for these attacks, we’ve to remember how works a TCP communication between the server and client. Basically a connection between two hosts (A and B) is composed by three steps: 1) Establishes a communication
Preventing brute force attacks with Fail2ban
Fail2ban help our servers to prevent the brute force attacks scanning the log files to find fail authentication attempts. Software like hydra http://www.thc.org/thc-hydra/ can attempt to login in service that require authentication like telnet, ssh, http, ftp, etc… trying with
Configure NAT in Linux
Hello everybody!! For today I’ll configure a Router Linux with NAT using Iptables and a simple port redirection. Basically NAT allow protect our network, translating a local IP network to another IP, changing the source IP of the packet headers.