The firewall is the cornerstone of security in computer networks and I.T in general. In this website I have been talking extensively about the Cisco ASA firewall which is a classic example of a hardware network firewall. However, there are some other types of firewalls used in large enterprises, SMB or even home networks. Some […]

Whenever Microsoft releases security patches even for unsupported Operating Systems (such as Windows XP, Vista etc) then you must act immediately (as a company or administrator) because it’s always a serious issue. This is what happened in May 14 when Microsoft released security patches for a critical software vulnerability affecting the Remote Desktop Protocol (RDP). […]

On this website I have written tens of articles about enterprise level firewalls (especially Cisco ASA) but many people are interested to learn about the best hardware firewalls for home or small business networks, so this is what I’ll focus in this article. Firewalls are designed to monitor incoming and outgoing traffic, helping to keep […]

NMAP (Network Mapper) is the de facto open source network scanner used by almost all security professionals to enumerate open ports and find live hosts in a network (and much more really). One of my responsibilities in my job is to perform white hat penetration testing and security assessments in corporate systems to evaluate their […]

Usually, in the world of network security, when we talk about Firewalls we mean the devices that help protect your computer systems and networks from attacks and provide a “wall” in front of servers and IT resources. The above concept of a “Firewall” refers to the classic network hardware firewall such as the Cisco ASA, […]

QUIC (Quick UDP Internet Connections) is a new generation Internet protocol that speeds online web applications that are susceptible to delay, such as searching, video streaming etc., by reducing the round-trip time (RTT) needed to connect to a server. By replacing TCP with UDP and encrypting most of its payload, QUIC reduces the time it […]

As a network security engineer, among tens of other tasks, I run also security assessment and penetration testing projects. One of the most popular and widely used network scanning tool is NMAP. This is one of the tools that I use at the beginning of a penetration testing engagement and helps tremendously in identifying targets, […]

On October 16, 2017 a serious security vulnerability has been published by researchers from KU Leuven, a university in Belgium. This has to do with WPA2 protection in WiFi networks, which is the modern security standard considered to be very safe so far. This vulnerability has to do with the WPA2 technology itself and is […]

Last week the whole world, and especially the information security community, has been buzzing around the massive ransomware attacks that infected thousands of computers in hundreds of countries. But how did all started? Many of you know the story, but let’s summarize it once again: NSA had developed some secret exploits that took advantage of […]

This tutorial marks the beginning of a series of network security and penetration testing articles that I will be posting on this website. The purpose of this article is to describe how to perform a simple NMAP scan of an IP range/subnet on a network. There are hundreds of scan options with NMAP but I […]