Access point dropping clients for no reason

ScumLord

I’m using a Buffalo wireless Access Point to provide Internet to some of the PCs in our office. In total there are 8 PCs and one WiFi skype phone on the network. Randomly the PCs are losing their connection with the AP. It’s strange in that it says it’s still connected but when you try to use the connection (including pinging any computer on the network) it’s dead. Some of these PCs also belong to a domain network where they access an access customer database.

The Network is set up using WPA-PSK(Tkip). There are a variety of adapters on this network ranging from Belkin to Buffalo and the problem is on all of them. I tried using AOSS with the Buffalo client software on the Client PCs but it only worked with the Buffalo Adapter (WLI-U2-G300N) which also has a fault, it won’t connect to the network unless I’m holding it by the usb cable I’m assuming that the usb port or cable does not fit correctly.

The ADSL modem is a seperate box that connects directly to the AP using a cable. The Modem is the DHCP server as the internet just won't work with the AP as the DHCP server.

I don’t understand why Clients are being dropped for no reason, is there a sleep function on the router? That wouldn't make to much sense though. Or are Buffalo products just crap?


I would appreciate any help you could provide.

http://support.microsoft.com/kb/821400 I came across this article about turning off "Wireless Zero Configuration service" which didn't work for me. It couldn't aquire an IP adress with that service off.

davis lu

How is the lost status? lost the connection with the AP for some time,and again some time later the PC connected again or just stay along lost?

mikebailey2000

I spent over a week and swapped out access points three times troubleshooting
frequent network drops and disabled laptop wireless cards.

Turns out the network was being attacked:

A hospital had rented space in the same building as one of Brian's clients,
and the hospital has a Cisco device which detects any nearby access points and
targets them as "rogues" and then hits them with a death flood.

We had to call the hospital and give them our MAC address so they would
classify us as a "friendly" access point and stop hammering us. This is
likely
to become an issue with anyone who uses this Cisco system, such as hospitals,
govt. security acencies, or mega-corporations.

I think the hospital uses a Cisco SWAN WLAN IDS, which "quickly detects,
locates, and automatically shuts down rogue access points."

See below:

"Jamming for Defense

One a side note, jamming is not just for malicious use. One way of
controlling
rogue access points in an enterprise is the flooding of packets to client
devices that are connected to a rogue access point. Some current wireless
network vendors include a method for creating a denial-of-service situation
for unauthorized wireless implementations by sending packets with the same
characteristics as a valid access points with disassociate packets. These
packets fool the client into thinking that the rogue access point doesn't
want
to communicate with the device anymore, effectively killing network
connectivty before it can be established. This is a very powerful feature
that
must be used carefully, as legal and political repercussions could arise."

We think the hospital may be breaking the law:

The operation of transmitters designed to jam or block wireless
communications is a violation of the Communications Act of 1934, as
amended ("Act"). See 47 U.S.C. Sections 301, 302a, 333. The Act
prohibits any person from willfully or maliciously interfering with the
radio communications of any station licensed or authorized under the Act
or operated by the U.S. government. 47 U.S.C. Section 333. The
manufacture, importation, sale or offer for sale, including advertising,
of devices designed to block or jam wireless transmissions is
prohibited. 47 U.S.C. Section 302a(b). Parties in violation of these
provisions may be subject to the penalties set out in 47 U.S.C. Sections
501-510. Fines for a first offense can range as high as $11,000 for each
violation or imprisonment for up to one year, and the device used may
also be seized and forfeited to the U.S. government.

Spread the word to all your tech buddies to be on the lookout for this
if you have any clients near hospitals, etc.

RogueFaye

the hostpital IS breaking the law. Imagine if you DOS their router, what would happen? You'll be up for claims.
They do not Own the airspace, that's so barbaric.