Build an Open Source Network Sniffer

An anonymous reader writes "This article reviews common issues of wireless security, and shows how to use open source software to suss out wireless networks, get information about them, and start recognizing common security problems. You will learn how build a lightweight wireless sniffer that runs on open source software and see how simple it is to interact with wireless networks."

Comments

Network "sniffer"?

[ZiZ]

While this tool that TFA references and builds is a pretty neat interface to viewing broadcast-SSID access points, I don't think it really qualifies as a 'sniffer', because it doesn't deal at all with sniffing packets, detecting non-broadcast-SSID access points, or anything along those lines.

It is, however, a pretty neat text-only interface to enumerate broadcasting APs, and honestly, the code for the interface makes for more interesting examination than the code for the 'sniffing'.

Re:What I really want

[ZiZ]

What you really want is something like NoCatAuth (described nicely by this article. There are plenty of other similar solutions out there - look for 'linux wireless authentication gateway' or something similar on your favorite search engine.

Wow, what a great article.

[thegnu]

I have bookmarked it. This is the kind of crap I love. I just today acquired a Cassiopeia E100 for free, and I'm going to a)install Linux on it, and b)see if I can get wireless running on it. This is gonna be awesome.

My favorite software slogan ever is for ethereal, "Sniffing the glue that holds the internet together"

I'm sure a lot of you know this but this is in reference to TCP/IP being called "the glue that holds the internet together" Oh so funny. And oh so off-topic. I'm sorry. I love you guys.

Re:What I really want

[heavy snowfall]

Try ipcop, it can split off your network into a wireless part and a wired part, and even add a third zone for public servers. The wireless part defaults to not giving access to either the internet or your other, wired computers, and you have to add mac addresses to a table for wireless clients to be able to connect. And it has nice graphs too, so you can see if someone's using your connection. Use this with WPA and vpn maybe. If you want more security, use wired lan instead.

Re:What I really want

[john_g_galt]

Sounds like you like something like this?

From the website above:

"NetReg is an automated system that requires an unknown DHCP client to register their hardware before gaining full network access. Through a simple web interface, the client is prompted for their user identification. Powerful scripts then retrieve the client's network fingerprint and store it along with the user's information in a database. The database provides administrators with real-time information for troubleshooting and auditing their networks. The entire system was developed utilizing unmodified, open-source servers and in-house developed CGI programs."

Linksys WRT54G/GS

[adamjaskie]

Its sold as a "router", but what it really is is a little plastic box with a 200MHz MIPS embedded computer running Linux. You can replace the firmware with something like Sveasoft's modified version, that allows you to SSH into it, and run something like Snort on it. You can turn off the onboard wireless card if you don't need it, and disconnect the antennas for an even more compact device. Without the radio going, it probably won't even put out much heat.