ARP spoofing attack and defense

As described in Wikipedia, ARP spoofing (otherwise known as ARP poisoning or Arp Poison Routing – APR) is a Layer 2 attack that can be carried out in most internal networks and therefore is extremely dangerous. It’s main purpose is to sniff the communication of a client talking to a server, by intercepting or even modifying the traffic in order to decrypt the already encrypted traffic. This article will guide you through the process of understanding, demonstrating and protecting your network against this attack. . . . → Read More: ARP spoofing attack and defense

DHCP starvation - quick and dirty

The DHCP starvation attack is quite simple to implement and therefore quite dangerous, especially if it grows to a DHCP spoofing attack. It can be used to implement a Denial of Service (DoS) attack against the DHCP server on the local network, thus preventing legitimate clients from accessing network resources. In this article we will demonstrate how this attack can be deployed and later we will go through the steps necessary to mitigate it on Cisco equipment with the help of DHCP snooping. . . . → Read More: DHCP starvation – quick and dirty

DTP - Share it

The one thing that is always overlooked, when someone tries to secure a network, is the user side. It is rare to see a DMZ network, that is protected by a firewall from the users. The general idea is that if you are an internal user, you have legitimate access to the servers, so there is no need to protect them from you. In this article we will discuss a frequently overlooked feature of Cisco switches called DTP, we will explain why is it dangerous and what are the steps to disable it. . . . → Read More: DTP – Share it