Wireless laptop using my broadband?

[onehunga]

Excuse my ignorance about all things wi fi (and networking) but here goes...

Had a friend over staying with me last night who has a new Acer Travelmate laptop with wireless connection. Now my flat has broadband ADSL at 512k through a USB "modem" and has done for a while. My pc is running Windows XP Pro and has zone alarm (free fire wall) set at the default values that it comes with. XP is up to date with the latest updates and SP's etc. Although my pc has the A7N8X-E Deluxe mobo I have NOT installed the wifi aerial (still in its box) and also in network properties the marvel software which I think enables (?) the wifi is showing a red cross so I guess that means it ain't configured properly too.

So anyway we are sitting in the lounge and my friends laptop auto detects a wifi connection to "conexant" network. No username or password is required and he is able to connect at something like 4 - 11 mbps I think it was.

Now my broadband modem is based on the conexant chipset. Do you think it is possible that somehow he was able to connect to my broadband without me even setting up wifi on my home pc?

The thing that threw me though was that when I disconnected from my ISP he was still connected to the internet and browsing ok. That made me think that in fact he was connected though someone else and not

Any ideas on things I should check and do in order to stop people being able to piggy back off my connection if in fact you think it is possible with the fire wall already installed etc?

Thanks in advance.

[pilot-lite]

Certainly sounds like a neighbour is running an open wireless network.

(Get yourself down to the local PC shop and pick up a wireless network card and cancel your broadband connection )

pilot-lite

[onehunga]

Well I am pretty certain I plugged the card in when I upgraded my pc and installed the new mobo. Just haven't installed the software or plugged in the aerial and hence no little logo in my taskbar at all telling me wifi is running.

Thinking more about it I suppose that I could install the wifi software disconnect my ADSL (even unplug the phone line to be sure) and if I can access the internet via wireless then I guess that proves that it is the neighbours system enabling me access?

Sneaky!!

[Naples Air Center, Inc.]

onehunga,

Great Mobo I am using it myself. The Marvel is the Gigabit Ethernet (1000BaseT). Which is the higher of the two NICs on the back place of the mobo. (The lower one is the nVidia 100BaseT NIC.)

Unless you plug in the 802.11b Adapter, you are not broadcasting wirelessly from that mobo.



Take Care,

Richard

[onehunga]

Thats what I was thinking as well. Borne out by the fact that my friend is around there at the moment and "surfing"whilst my pc is cold and dark and I am at work!

As an aside when you install the wifi software and adapter I saw somewhere that there were secure keys or something along those lines that get created. Do you make these up and give them to people/other equipment that you want to access thereby preventing unwanted people to eves drop on my connection? There wasn't much on the asus website about the wifi setup at all so presumably the guidance will still be sitting in the mobo box?

Thanks all.

[Naples Air Center, Inc.]

onehunga,

If you use WEP, the other computer will need the Encryption Key in order to connect wirelessly. Another option would be to enter the MAC Address of the Notebook computer so only that computer can log on wirelessly.

Take Care,

Richard

[BEagle]

Richard - is MAC address restriction a reasonable level of security for the domestic user? The BT Voyager 2000 which I use is a single box which contains both the W-LAN router and the Broadband modem. I have set it to 'talk' only to 2 defined 'wireless clients' using their MAC addresses and have set a normal level of firewall security in the configuration set-up. Is WEP really needed in addition?

Presumably the easiest way to add a normal PC to this is just to add a wireless card (it's an 802.11b system) to the PC tower and then to add the card's MAC address to the list of 'wireless clients'?

[Evo]

BEagle -

A MAC address access control list is not real security. MAC addresses are in plain text in each network packet, so an attacker just needs to to examine the network traffic and spoof an allowed MAC address.

Likewise, 'closing' the network by disabling SSID broadcast can also be easily defeated. Both these options are really just an illusion of security through obscurity - the casual user cannot access your network, but anyone with an interest can break in trivially.

Static WEP has it's problems, but it's not as easily defeated as the other basic 'security' options. None of these are suitable for business use, but they may be fine for home use. Is anybody really likely to try and access your home wireless LAN?

[Saab Dastard]

Another couple of ways to help prevent unauthorised use of wireless networking would be to limit the number of DHCP addresses allocated to the number of genuine wireless / wired clients, and to choose an internal network addressing scheme and subnet mask to limit the number of nodes on your network.

These are not insurmountable - just make it that much more effort for a miscreant to get access to your wireless network.

SD

[Naples Air Center, Inc.]

BEagle,

If you want network security, go wired. Limiting MAC addresses does not stop someone from reading your wireless traffic, (since it is not encrypted). But, it keeps honest people from logging on to your Wireless Network.

WEP while having its security issues, does at lease encrypt your data. That along with limiting MAC Addresses, is a little bit more secure but it will not keep advanced hackers out of your network.

Then again, what do most advanced hackers want with someone's home network? They are not looking for a small home network. They, 99.9% of the time, want a business or government network.

Take Care,

Richard

[BEagle]

Thanks, Richard - that's exactly as I thought. MAC address restricting is good enough for me as there's nothing of any commercial or other sensitive nature on my systems.

I just hope that these wretched 'advanced hackers' will one day be caught - and then financially ruined before being imprisoned for a very long time!