Author: Matej Šipkovský

My name is Matej Šipkovský and I am a founder of this blog about network technologies NETVEL.SK. I am particularly interested in implementing network solutions and network security for corporate clients.I studied at the Slovak Technical University in Bratislava at the Faculty of Electrical Engineering and Information Technology with specialisation in Telecommunications, where I completed my engineering studies. During this time I completed the Cisco CCNP Routing & Switching certification and later came with CCDA, CCNA Security and Fortinet Network Security Professional NSE4 certification.

MAC Flooding & Port Security – Ethernet switch vulnerability

MAC flooding is an attack that manipulates the behaviour of the ethernet switch so that the traffic that passes through it can be captured. In this article, we’ll show how this attack looks and how to effectively protect our devices against it.

MAC flooding macof

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CDP flooding – DoS attack overloading CPU

CDP flooding is a DoS attack using vulnerability of the CDP protocol, which is turned on by default on most of the Cisco devices. After the attack is started, the CPU of the target device is 100% saturated, preventing it’s normal operation. We will show how this attack can be launched and how to protect your devices against it.

CDP flooding CPU history

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HSRP attack – vulnerability of the network redundancy protocol

HSRP (Hot Standby Router Protocol) is a Cisco proprietary protocol that provides network redundancy in case of default gateway router failure. It is one of the most common protocols, however, it contains vulnerability that can lead to denial of service or to data capturing by attackers. We will show you how the HSRP attack can take place and how to protect your network against it.

HSRP attack topology

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DoS attack from inside the network to a DHCP server

How to trick the DHCP server to not provide IP address  to devices, what will completely block new connections? It could be done by DoS attack called “DHCP starvation attack“. We will show you how to do it and how to protect your network.

DoS attack messages

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ARP spoof attack – Capturing network data

Is it possible for someone to capture your entire network or internet communication? Yes it is! With ARP spoofing it is very easy. Only 4 CLI commands are needed.

We will show it on a simple example. We will capture communication between router R1 and switch SW1. Our attacking host is called KALI.

Let’s say we want to capture the admin username and password that logs in from SW1 to R1 using TELNET, which is unencrypted.

ARP spoof

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How to hack password of your router

How do hackers know how to take control of your device, even if they are thousands of miles away? If you are careless and expose your devices to this threat, you may be sure that someone will try to do that. Here’s how to hack password and username of network devices with dictionary attack.

How to hack password

Photo by CafeCredit under CC 2.0

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How to hack wifi – Breaking the WPA2 – PSK keys

Is it safe to use WIFI on connections that you don’t want someone to capture? Or can your WIFI network introduce a security breach that opens the door to an intruder into your systems? If you don’t follow some recommendations, it could happen very easy. We’ll show you how to hack WIFI.

How to hack wifi

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