Network packet sniffing with Linux

Here’s a chance to learn a little bit about network security. This article walks us through some of the core concepts of network manipulation and packet sniffing using Linux tools. [Joey Bernard] discusses the uses for packages like tcpdump, p0f, and dsniff. They are capable of recording all network traffic coming through your computer’s connection, seeking out machines installed on the network, and listening to traffic for a specific machine. This isn’t going to give you a step-by-step for cracking modern networks. It will provide some insight on what is going on with your network and you should be able to purpose these tools to check that you’ve got adequate security measures in place.

This is a peer-to-peer filesharing network

[Aram Bartholl] is building his own filesharing network that screws those fat cats who want to control your freedom. He’s added file cache devices throughout NYC (five so far but more to come) that are anonymous and free to use. Upload what you want, download what you want. They’re completely offline which means monitoring who’s doing what gets a lot harder and quite possibly requires a warrant from a Judge (we’re obviously not legal experts, your mileage may vary).

As for the slew of comments that are sure to point out the dangers of malicious USB device; We think everyone knows they’re taking on some risk when connecting to a USB plug protruding from a brick wall.

[Thanks Neckbeard]

Ethernet connection using capacitive coupling

Wanting to save space and weight on his project build [Florin] set out to find a way to add Ethernet connectivity without the magnetics. His ill-advised first try involved directly coupling two switches, frying both in the process. After some research he found that Ethernet hardware manufacturers have considered the need for devices without the magnetics and there are several application notes available on the subject. [Florin] followed the information that Realtek has for their devices and learned that they can be couple capacitively. After depopulating the magnetics from a second pair of switches he wired up some resistor-capacitor networks on a breadboard and got the connecting to work.

Network enabled window air conditioner

It’s no secret that the central US is feels like a very humid oven right now. [Erik’s] window AC hack might help you out if you’re coping with triple-digit temperatures. He added network connectivity to the unit above but the picture is a bit deceiving. The blue CAT-5 cable that enters the bottom isn’t connecting directly to the network, but extends the up and down button connections for the unit to an external relay board. From there he uses an SNMP board to connect it to the network and uses PHP commands to reset the temperature. The unit has a working range of 66-88 degrees Fahrenheit so he cycles enough button press to reach the maximum or minimum level, then sets the desired temperature (avoiding the need to know what temperature the unit is currently set at).

If you’ve got an AC unit with a remote control you could always use an IR device to patch into the system for similar functionality.

2010 Ninja Party badge

Wired took a look at this year’s Ninja Party badges. We were giddy about all the goodies involved in last year’s must-have badge that served as an invitation to the party. It was tailor-made for hacking, including an on-board disassembler. This year’s details are still a bit sparse but the offering is more along the lines of a market-ready product. The badges come in hand held gaming format, with a d-pad and two buttons. They can connect wirelessly with each other and with hidden base stations, allowing participants to fight in the digital realm for LED-indicated achievements. The teaser is tantalizing and we can’t wait to hear details about the real/digital gaming adventure soon to unfold.

Microcontrollers access the web

[Kenneth Finnegan] is back with another video showing some cool stuff he’s doing to connect his microcontrollers to the internet. Usually, we see this done with a prebuilt module like an iobridge. [Kenneth] is using a Microchip ENC28j60 module for the communication and he’s managed to stuff it all onto a tiny Electroboards piece.  [Kenneth] is starting to become a regular around here.

[via HackedGadgets]

RFID tracking system

[Nicholas] built an active tracking system using RFID tags. The system’s tags operate in the 2.4 GHz band and are used to track either people or assets. The readers are on a mesh network and can triangulate the location of any tag for display on a map. His system is even set up to show the travel history of each tag. [Nicholas] shared every detail in his writeup including some background about available hardware options and how he made his final decisions on what devices to use for the job. His conglomeration of software that ties the whole project together is also available for download.