In order to get onto a university's wireless system, I would have to give the sysops the identity of my computer, which looks something like
00:bc:44:e3:ad:21
If they have access to every wireless access point in the world, yes.
What terminal?
The OS running on the access point?
Depends on your wireless card.
Juergen Nieveler
sysops the identity of my computer, which looks something like
if they know this hardware address?
It's not the government you have to worry about, it's people that want into your machine from any walk of life. Anyone that knows your MAC or your workstation name, can see you on their network. The MAC does not extend beyond your local network, so you don't have to worry about someone outside of it seeing it.
Possibly - it depends on how your OS/System is setup.
Network sniffers, tracing apps, etc.... If your computer registers it's connection with the DHCP or DNS server then it's very easy to see it's you. Then there is the fact that you are broadcasting information about your identity all over the airwaves....
I depends on the card you use and if it permits it - some do, some don't. It won't matter unless you are wearing a foil hat or at least one made of copper.
The software is built into the routers or access points. They get a list of all the MAC addresses that are allowed to use the university network, and ignore any other machines. This is done to prevent the network from being a public hotspot that anyone can hook into.
That's your MAC address. Start here:
they know this hardware address?
No. The client MAC address is not transmitted in the TCP/IP packet header. Only the ethernet packet header contains the source MAC address and that ends at the switch or router.
However, the university switch or router has a table of connected MAC addresses and associated IP addresses (ARP table) that can be used to point to your machine. It will certainly point to the access point to which you're connected. The rest of the world will not be able to find you because they do not have access to the university switch information, but the university can certainly get close.
Also, most universities use some form of proxy server and authentication login for users to connect to their system. This will identify the "portal" to which you're connecting and furthur help locate you computer.
I've also done some work with direction finding of 802.11 and suspect that you can be easily located if you don't take any countermeasures.
Be advised the wonderful people at Microsoft imbed tracking information in the header of any MS Word, Excel, PowerPoint, and Access file that is unique to your machine and can be used to positively identify the machine of origin.
Of course. They can sniff all the traffic to and from your machine. Most university systems are NOT encrypted, but might go through a VPN. If the VPN termination is at a university server, they can capture all your traffic.
If you mean can they dive into your computer and snoop around, that is largely a matter of how secure or insecure you setup your computah. An amazing number of Windoze boxes have open shares or disabled firewalls that are easily accessible.
Ummm... To identify your computer? None. They are not trying to identify the machine. They're interested in identifying the user. When you login to the university network, you identify yourself. The idea is that you can sit in front of any machine, login, and you get to use the university network. The probably do log the MAC address of the machine you're using.
Sure. Windoze does not use the MAC address on the card. It uses whatever it excavates from the registry. Wanna spoof a MAC address?
Incidentally, I have a friends son who got burned in one of the "zero tolerance" stupidities at his university. They had a ban on *ALL* MP3's on university ftp or web servers. He's a music student and placed some of his own compositions on his web server and was caught by the university robot security daemon. It took about 3 months to get his computer access back even though the university admitted that it was a proper exception.
sysops the identity of my computer, which looks something like
they know this hardware address?
No.
If you let them in.
???
Yes, you can spoof your address if you have the right card, but why?
The harware address is used to address your machine on the local net (ie after the ip address has narrowed it down to your local net)
Do you remember when the MAC address was also part of Microsoft Word document headers?
David.
To what end? The network administrator needs to know a MAC address in order to associate your computer to the network. Whatever MAC address you use, whether the factory assigned MAC address, or the one you spoof; they will have it, and know which computer it belongs to.
Well, it goes a bit deeper than that. One of the more obnoxious problems at universities is that student install wired or wireless routers in their dorm rooms with NAT. Nothing really wrong with that except that it totally destroys the MAC address based authentication mechanism. The MAC addresses just don't go through the router. Some universities ban the use of such routers, while others concoct different methods of authentication or try to "discover" how many machines are hidden behind the NAT firewall. This can be done in various devious ways. The easiest is to setup a VPN server to access the university network. The user has to login in via a VPN client, which will merrily disclose all kinds of useful information including the MAC address.
See:
Most universities also run "arpwatch" on their networks. Any new MAC addresses that appear on their DHCP server gets logged. If they fail to authenticate, they get blocked after a few days. Works nicely to keep the unauthorized machines out of the university network.
Digging deeper was the 1999 attempt by Comcast to bill their customers by the number of computers that were running on their home network. If they discovered more than one machine, some telemarketing group would phone the customer demanding an extra $6/month per machine. Comcast would rather forget they ever attempted such nonsense, but it did bring up some interesting technology for detecting and identifying machines behind a firewall or router. Most interesting was watching the pattern of TCP/IP sequence numbers. Less interesting but more effective were web pages that would try to identify client computers.
As for finding a users location, it's much easier than one would suspect with the proper hardware. I've been doing some work with RFC3825, which is a DHCP extension for location services. The original idea was to have the AP disclose it's exact location to the wireless client. The client then transmits the location to whomever needs the information, such as the 911 center for a VoIP call.
Not unless he spoofs someone else's MAC address. They'll have *an* address but won't know which computer it belongs to.
Unless they bother to hunt him down by triangulating his position via the access points. (or trace him down the copper path).
David.
Correct. That's all that's required for VoIP 911 service. Note that the AP DHCP data include floor number or altitude which is critical for emergency services.
However, the AP might be capeable of measuring the latency to/from the client and establishing a radius (actually a spherical surface). Two or more radii can be used to establish a position. It's a bit of a problem doing it in 3 dimensions, but not impossible. It really depends on how much technology you want to throw at the problem.
I didn't know they did that. I couldn't find much about triangulation and their "RF Topology Mapping" on their web pile.
Oh, they're using signal strength. Bad idea because of reflections, wall attentuation, non-isotropic antenna patterns, and interference effects. It will probably be sufficient for locating rogue AP's, laptops, and PDA's in an office building environement, but forget it if the client has a highly directional antenna. Still, it's better than manual guesswork. Have you tried it? Duz it work?
You can use different MAC for different networks. Your movements can't be tracked, unless the netops correlate their log files, which seems unlikely to ever happen.
But then you must play the game to the bitter end: use different application layer identifiers, different writing style, etc. Why bother...
-- Lassi
sysops the identity of my computer, which looks something like
if they know this hardware address?
Destroy all of that equipment immediately! Before the Germans find it!
Checking on two is not that much more difficult than one.
triangulate? This is not a cell phone. The range of an access point is severely limited.
None the less, access-point triangulation is possible. Cisco's WLAN controller advertises it as a feature, indirectly. The technology was developed to detect rogue access-points and rogue endpoints. The Cisco/Linksys technology correlates received signal strengths at access points and endpoints.
Excpt that the signal strength varies a lot depending on the exact orientation of the antenna in the endpoint wrt the accesspoint ( and various other things), and this need not be the same for each AP (reflections, etc)
He could arrange to spoof just about every MAC address that he sees. I can cite an example of a college that had 700 MAC's on the LAN but the administrator had only approved 400 devices.
Yes triangulate to locate the user. How far do you think an AP can transmit?
David.
Go take a look at the Trapeze Networks stuff, they claim location accuracy down to 0.6m and it shows a nice big arrow to the location on an imported CAD building plan that was used in the Ringmaster software to plan the wireless solution.
I have no experience of Airespace (bought by Cisco) but they claim better.
David.
That's only going to give you the location of the user as defined by the AP that they are using though is it not?
Trapeze does it by triangulation of the RF signal from 3 (or more) mobility units (their name for their dumb AP's).
Because the Ringmaster software is used to configure these, you import a plan of the building and define all the RF obstacles thus the software not only calculates in 3D, the location for the radios and also the power output of each (and tunes them at runtime if so set), they can also determine the location of a given client pretty easily.
David.
That is still just 2-1.
Not far enough that at least three of them are in range.
Admittedly once you know which access point is being used you know where he is within about 20 meters.
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