I will Networking 2 computers soon using a 4-Port ADSL/Router. I do on-line banking and I know that wireless is not as secure as wired. I will have Computer #1 wired and Computer #2 wireless. Only Computer #1 will be doing banking. My question is, because Computer #1 is wired does anything escape via the wireless into the outside world. Can Computer #2 see what #1 is doing. Can Computer #2 transmit anything that #1 is doing.
Many Thanks

You know I've never thought about that and would have assumed that no, but to be honest I'm not so sure. Have you tried having a look what you get when you scan for network traffic from comp #2 with a program like Ethereal? http://www.ethereal.com/download.html

You might be able to tell from the protocols being used what information is being transmitted.

Adam

Maybe LAN broadcasts but that's it. What would be more worrisome to me about the wired computer is a wardriver hacking into the wireless network, and then hacking the wired computer since they're now connected into the network. All it takes is planting a keystroke logger, and you entering your user name and password.

In that light, it really doesn't matter if you do online banking on the wireless or wired computer. If the banking connection is done SSL, if you're on wireless, it's still encrypted. If you don't trust that, you shouldn't trust SSL over the internet for secure connections no matter if you're wired or wireless.

What you want therefore is to secure your wireless network so wardrivers can't get into the LAN of your network. You want to ensure that you use wifi encryption. I would highly recommend getting a Wireless Access Point and wifi card (if your current one doesn't support it) that both support WPA-PSK encryption. WEP is now easily hackable with tools that can crack the encryption key in minutes.

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The only thing that the wireless computer will be able to see coming from the network is broadcast packets. If you download ethereal on the wireless computer, and choose to capture packets using your wireless interface in promiscous mode, you will see the broadcasts being sent to every host on the subnet. This is the same for the reverse case. The wired computer will be able to broadcast packets originating from the wireless computer.

Now, if both computers were wireless and you captured packets on one computer, you would 'probably' see all traffic generated from the other wireless computer. This is because the radio frequency that your wireless LAN is using is considered shared medium.

When the AP/Router goes to forward a packet to a wireless client, that packet has the destination MAC and IP address of the intended recipient and the packet gets forwarded out the wireless interface. Once it hits the air, all computers connected to that AP/Router will 'see' the packet and process as much of the packet necessary to determine whether or not the packet is intended for that host. This is identical to the way broadcast packets are processed.

If two computers were wired to a switched Ethernet network, one PC would not be able to see unicast traffic from the other PC due to the theory of switching because each device connected to a switch has the full port bandwidth available and is not sharing medium.

Hope that helps.

If they can get on your wireless network, they can see what is going on with the entire network. Set an encryption key for your wireless...

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It's not enough anymore to simply say encrypt it. WEP will keep most out, but it's very common now for it to be broken. WPA-PSK should be used...well, until it's broken. :-)

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