Computer in Network Cannot connect

[powerwalk]

Need some input please. I’m attempting to help a friend with her network
which consists of an XP desktop and two Vista laptops. They’ve been networked
in this manner for over a year sharing internet, files and printer through a
linksys wireless gateway.

The network has performed well until last week when just one of the laptops
could no longer connect to the network...it could connect to unsecured
neighbors networks, however, and it still has the ability to attempt to
connect to the network name but without success.

The encryption is WEP with hidden network and MAC filtering. When the
network is no longer hidden and MAC filtering is disabled, it does connect
using the network. But I can’t seem to restore the original network settings
so that the laptop will connect in the future after MAC filtering is turning
back on and the network name is hidden. The new connection software will not
accept the WEP key, and yes, I’m sure the key is correct.

The two other computers are fine, there is no software update for the
linksys, under network properties the setting is still showing ‘connect to
this network’, the computer’s MAC address still shows in the filtering list
as allowed I’m totally stumped.

 

[Jack [MVP-Networking]]

Hi
Hidden Network (SSID Off) is Not a security at all, and in most cases
destabilize the Wireless Network.
MAC filtering is Not real security either. It would deter few Neighbors that
know nothing about computers, but that is about it.
WEP can be easily broken by knowledgeable users, but it is much better than
the two methods mentioned above.
Any one who can brake WEP can in few second by bypass the first two
mentioned, so if WEP is used the first two are really nothing.
If the person can Not connected to his own Network, and can connect to
someone else's, it means that his/her WEP (or WPA) is not functioning
correctly.
Maybe this can Help, http://www.ezlan.net/wireless.html.
In general.
From the weakest to the strongest, Wireless security capacity is.
No Security
Switching Off SSID (same has No Security. SSID can be easily sniffed even if
it is Off)
MAC Filtering______(Band Aid if nothing else is available, MAC number can be
easily Spoofed).
WEP64____(Easy, to "Break" by knowledgeable people).
WEP128___(A little Harder, but "Hackable" too).
-------------------
The three above are Not considered safe.
Safe Starts here at WPA.
-------------------
WPA-PSK__(Very Hard to Break).
WPA-AES__(Not functionally Breakable)
WPA2____ (Not functionally Breakable).
Note 1: WPA-AES the the current entry level rendition of WPA2.
Note 2: If you use WinXP bellow SP3 and did not updated it, you would have
to download the WPA2 patch from Microsoft.
<http://support.microsoft.com/kb/893357>
The documentation of your Wireless devices (Wireless Router, and Wireless
Computer's Card) should state the type of security that is available with
your Wireless hardware.
All devices MUST be set to the same security level using the same pass
phrase.
Therefore the security must be set according what ever is the best possible
of one of the Wireless devices.
I.e. even if most of your system might be capable to be configured to the
max. with WPA2, but one device is only capable to be configured to max . of
WEP, to whole system must be configured to WEP.
If you need more good security and one device (like a Wireless card that can
do WEP only) is holding better security for the whole Network, replace the
device with a better one.
Setting Wireless Security - http://www.ezlan.net/Wireless_Security.html
Jack (MVP-Networking).

 

[powerwalk]

I thank you so much for taking the time to attempt to help me. I did check
all areas suggested in your post before seeking help here.

As you will note, I said this setup has worked for well over a year, and the
other laptop in the network was purchased at the same time, is the same
model, etc, and is experiencing no problems connecting ditto the desktop

Unfortunately, the gateway is about six years old and my friend sees no need
to upgrade. In fact, earlier this year I expressed concern over the WEP
security. She called linksys and was told for her usage of the computer this
was an acceptable setup.

I guess my next move would be to remove and reinstall the network on just
the one computer. Any additional thoughts are welcome.