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Completly block signal.

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Anonymous
a b F Wireless
July 20, 2004 4:57:19 PM

Archived from groups: alt.internet.wireless (More info?)

Any suggestions on how to completly block a signal. I have a device
that I wish to use its ethernet and turn off its wireless (leaving it
on leaves security problems) but there is no option in its
configuration to do this. I've removed the antenta and tried covering
the hole with aluminum wrap, but still got a signal from a good
distance. I need to have no signal from any distance (or atleast no
signal from 10 feet away seriously).

Any suggestions.

More about : completly block signal

Anonymous
a b F Wireless
July 20, 2004 8:53:19 PM

Archived from groups: alt.internet.wireless (More info?)

"John Larsen" <jlarsen@fsu.edu> wrote in message
news:1b151b59.0407201157.7868bc61@posting.google.com...
> Any suggestions on how to completly block a signal. I have a device
> that I wish to use its ethernet and turn off its wireless (leaving it
> on leaves security problems) but there is no option in its
> configuration to do this. I've removed the antenta and tried covering
> the hole with aluminum wrap, but still got a signal from a good
> distance. I need to have no signal from any distance (or atleast no
> signal from 10 feet away seriously).
>
> Any suggestions.

Maybe a large iron/steel box like they use for electrical panels would work.
It might be easier and cheaper in the long run to get a small router and
just use that instead of the wireless one.
Here's an idea. Sell the wireless router on Ebay and use the money to buy a
wired one.
:-)
AG
July 20, 2004 9:11:49 PM

Archived from groups: alt.internet.wireless (More info?)

if its a laptop, take the wireless card out... or go into the hardware tap
and disable the wireless card.. when you want to use wireless again, go
back and enable the card
"John Larsen" <jlarsen@fsu.edu> wrote in message
news:1b151b59.0407201157.7868bc61@posting.google.com...
> Any suggestions on how to completly block a signal. I have a device
> that I wish to use its ethernet and turn off its wireless (leaving it
> on leaves security problems) but there is no option in its
> configuration to do this. I've removed the antenta and tried covering
> the hole with aluminum wrap, but still got a signal from a good
> distance. I need to have no signal from any distance (or atleast no
> signal from 10 feet away seriously).
>
> Any suggestions.
Related resources
Anonymous
a b F Wireless
July 20, 2004 9:58:46 PM

Archived from groups: alt.internet.wireless (More info?)

"John Larsen" <jlarsen@fsu.edu> wrote in message
news:1b151b59.0407201157.7868bc61@posting.google.com...
> Any suggestions on how to completly block a signal. I have a device
> that I wish to use its ethernet and turn off its wireless (leaving it
> on leaves security problems) but there is no option in its
> configuration to do this. I've removed the antenta and tried covering
> the hole with aluminum wrap, but still got a signal from a good
> distance. I need to have no signal from any distance (or atleast no
> signal from 10 feet away seriously).
>
> Any suggestions.

Which router are you using? Some (like Linksys) have third party firmware
which will allow you to do this.
Anonymous
a b F Wireless
July 21, 2004 1:02:10 AM

Archived from groups: alt.internet.wireless (More info?)

jlarsen@fsu.edu (John Larsen) wrote in message news:<1b151b59.0407201157.7868bc61@posting.google.com>...
> Any suggestions on how to completly block a signal. I have a device
> that I wish to use its ethernet and turn off its wireless (leaving it
> on leaves security problems) but there is no option in its
> configuration to do this. I've removed the antenta and tried covering
> the hole with aluminum wrap, but still got a signal from a good
> distance. I need to have no signal from any distance (or atleast no
> signal from 10 feet away seriously).
>
> Any suggestions.

Yep, dummy loads. Get a of 50 ohm carbon resistors and remove the
antenna and replace it with the 50 ohm resistor. Mind you ten feet is
just this side of, how dumb is this desire?
Anonymous
a b F Wireless
July 21, 2004 1:02:19 AM

Archived from groups: alt.internet.wireless (More info?)

jlarsen@fsu.edu (John Larsen) wrote in message news:<1b151b59.0407201157.7868bc61@posting.google.com>...
> Any suggestions on how to completly block a signal. I have a device
> that I wish to use its ethernet and turn off its wireless (leaving it
> on leaves security problems) but there is no option in its
> configuration to do this. I've removed the antenta and tried covering
> the hole with aluminum wrap, but still got a signal from a good
> distance. I need to have no signal from any distance (or atleast no
> signal from 10 feet away seriously).
>
> Any suggestions.

Yep, dummy loads. Get a of 50 ohm carbon resistors and remove the
antenna and replace it with the 50 ohm resistor. Mind you ten feet is
just this side of, how dumb is this desire?
Anonymous
a b F Wireless
July 21, 2004 1:02:25 AM

Archived from groups: alt.internet.wireless (More info?)

jlarsen@fsu.edu (John Larsen) wrote in message news:<1b151b59.0407201157.7868bc61@posting.google.com>...
> Any suggestions on how to completly block a signal. I have a device
> that I wish to use its ethernet and turn off its wireless (leaving it
> on leaves security problems) but there is no option in its
> configuration to do this. I've removed the antenta and tried covering
> the hole with aluminum wrap, but still got a signal from a good
> distance. I need to have no signal from any distance (or atleast no
> signal from 10 feet away seriously).
>
> Any suggestions.

Yep, dummy loads. Get a of 50 ohm carbon resistors and remove the
antenna and replace it with the 50 ohm resistor. Mind you ten feet is
just this side of, how dumb is this desire?
Anonymous
a b F Wireless
July 21, 2004 1:02:30 AM

Archived from groups: alt.internet.wireless (More info?)

jlarsen@fsu.edu (John Larsen) wrote in message news:<1b151b59.0407201157.7868bc61@posting.google.com>...
> Any suggestions on how to completly block a signal. I have a device
> that I wish to use its ethernet and turn off its wireless (leaving it
> on leaves security problems) but there is no option in its
> configuration to do this. I've removed the antenta and tried covering
> the hole with aluminum wrap, but still got a signal from a good
> distance. I need to have no signal from any distance (or atleast no
> signal from 10 feet away seriously).
>
> Any suggestions.

Yep, dummy loads. Get a of 50 ohm carbon resistors and remove the
antenna and replace it with the 50 ohm resistor. Mind you ten feet is
just this side of, how dumb is this desire?
Anonymous
a b F Wireless
July 21, 2004 1:13:13 AM

Archived from groups: alt.internet.wireless (More info?)

In article <1b151b59.0407201157.7868bc61@posting.google.com>,
John Larsen <jlarsen@fsu.edu> wrote:
:Any suggestions on how to completly block a signal. I have a device
:that I wish to use its ethernet and turn off its wireless (leaving it
:o n leaves security problems) but there is no option in its
:configuration to do this. I've removed the antenta and tried covering
:the hole with aluminum wrap, but still got a signal from a good
:D istance. I need to have no signal from any distance (or atleast no
:signal from 10 feet away seriously).

You want Tempest class shielding. Except that you won't be able to
buy it under that name or even find out what it's specifications are
unless you are in the military and have a Need To Know.

What you -can- buy is a Faraday Cage. That'll certainly -reduce- the
signal; I don't know if you'd be able to get it down to "no signal"
at 10 feet.

Our heavy duty shielding here is aimed more at magnetic fields than
electric. It's made out of a steel and nickel alloy or something like
that, and it is *very* expensive.

I don't have even close to a high enough security clearance to know what
our our government agents use for signal shielding; the closest I get to
that is that I know one fellow who will say only that "Yes, I used to work
for them, and I can't tell you anything about what I did."
--
What is "The Ultimate Meme"? Would it, like Monty Python's
"The World's Funniest Joke", lead to the deaths of everyone who
encountered it? Ideas *have* lead to the destruction of entire cultures.
-- A Child's Garden Of Memes
Anonymous
a b F Wireless
July 21, 2004 7:32:43 AM

Archived from groups: alt.internet.wireless (More info?)

> :Any suggestions on how to completly block a signal. I have a device

Lol :)  Others would give alot to have a stronger signal and you want to
competely block it... Buying an UTP router would do I guess.

> Our heavy duty shielding here is aimed more at magnetic fields than
> electric. It's made out of a steel and nickel alloy or something like
> that, and it is *very* expensive.

I've read about wallpaper that stops radio signals from getting out. It's
made from the same material as Stealth bombers and is claimed not to be too
expensive.


Rens
Anonymous
a b F Wireless
July 21, 2004 10:10:14 AM

Archived from groups: alt.internet.wireless (More info?)

On 20 Jul 2004 12:57:19 -0700, jlarsen@fsu.edu (John Larsen) wrote:

>Any suggestions on how to completly block a signal. I have a device
>that I wish to use its ethernet and turn off its wireless (leaving it
>on leaves security problems) but there is no option in its
>configuration to do this. I've removed the antenta and tried covering
>the hole with aluminum wrap, but still got a signal from a good
>distance. I need to have no signal from any distance (or atleast no
>signal from 10 feet away seriously).

What's a "device"? Is that like a wireless router or bridge? If so,
just configure the MAC address filter to only accept connections from
one MAC address. Make it one that will never be issued. The result
is that nobody connects.

--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831.336.2558 voice http://www.LearnByDestroying.com
# jeffl@comix.santa-cruz.ca.us
# 831.421.6491 digital_pager jeffl@cruzio.com AE6KS
Anonymous
a b F Wireless
July 21, 2004 2:38:25 PM

Archived from groups: alt.internet.wireless (More info?)

Best Idea is repeated in the replies in this thread your asking about, I
aggree.

if you cant switch off the wireless

Use a 50ohm resistor, I am sure if you can obtain one of these and somehow
get a "spare" antenna you can remove the antenna bit from the spare, and
solder in the resistor so that it "Shorts" the center pin to the ground
brass sleeve. This way your wireless has a "Perfect match" and will not
damage the wireless card..

Do some googling on Dummy loads and you will understand then about 50ohm and
75ohm radio transmitters and how they are matched, a dummy load will not
radiate, apart from miniscule ammounts. esp at 2.4ghz and will be a perfect
match.

Opinions by HubSwitch
(Radio Amateur)



"John Larsen" <jlarsen@fsu.edu> wrote in message
news:1b151b59.0407201157.7868bc61@posting.google.com...
> Any suggestions on how to completly block a signal. I have a device
> that I wish to use its ethernet and turn off its wireless (leaving it
> on leaves security problems) but there is no option in its
> configuration to do this. I've removed the antenta and tried covering
> the hole with aluminum wrap, but still got a signal from a good
> distance. I need to have no signal from any distance (or atleast no
> signal from 10 feet away seriously).
>
> Any suggestions.
Anonymous
a b F Wireless
July 21, 2004 2:38:26 PM

Archived from groups: alt.internet.wireless (More info?)

On Wed, 21 Jul 2004 10:38:25 +0100, "HubSwitch"
<Hubswitch@isa-geek.qwerty.co.uk> wrote:

>Use a 50ohm resistor, I am sure if you can obtain one of these and somehow
>get a "spare" antenna you can remove the antenna bit from the spare, and
>solder in the resistor so that it "Shorts" the center pin to the ground
>brass sleeve. This way your wireless has a "Perfect match" and will not
>damage the wireless card..

Just a minor note or two. A short circuit is NOT a perfect match. In
fact, it's infinite VSWR or as bad a match as an open circuit. The
prefect match for most wireless cards is 50 ohms. An unterminated
coax will radiate quite nicely, as will a shorted coax. Terminated
with 50ohms, it will radiate less, but it's far from zero radiation.

However, there are few problems with using a 50 ohm terminator.

1. Finding a 50 ohm terminator in a reverse-SMA or reverse-TNC
connector is gonna be difficult. When testing radios, I had to make
my own as none of the vendors had them in stock. When I got weird
results, I eventually put my home made terminators on the network
analyzer and found them to be anything but 50 ohms. Finding a 50ohm
resistor that is still 50 ohms at 2.4GHz is a problem. Building it
into a connector so that it's part of 50ohm transmission line, is also
a problem. The best I could do was with a solid wire center pin
extension, and 4ea 200ohm resistors soldered radially between the
center wire and the connector shield and that wasn't good enough. So,
I used a real terminator in an N-connector, and a mess of adapters.

2. In the DWL-900AP+, there are actually TWO antennas. One goes to
the outside R-SMA connector and is easily accessible. The other is
inside the case and is NOT easily accessible. (Note: Internal=left,
External=right). The two antennas are both active and part of a
diversity system. You would need to disable the internal antenna in
the web based setup to make sure it doesn't function.

3. Even terminated, some radios still radiate quite a bit. I just
removed the two antennas from my BEFWS11, and installed a pair of
terminators (actually a pair of 50ohm 6GHz N-Terminators and an N to
R-TNC adapter). I lose connection with my laptop at about 20ft.
Longer range testing will require that I put my shoes on and make
myself presentable.

>Do some googling on Dummy loads and you will understand then about 50ohm and
>75ohm radio transmitters and how they are matched, a dummy load will not
>radiate, apart from miniscule ammounts. esp at 2.4ghz and will be a perfect
>match.
>Opinions by HubSwitch
>(Radio Amateur)


--
Jeff Liebermann jeffl@comix.santa-cruz.ca.us
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558
Anonymous
a b F Wireless
July 21, 2004 2:59:33 PM

Archived from groups: alt.internet.wireless (More info?)

On Wed, 21 Jul 2004 10:38:25 +0100, HubSwitch wrote:

>
> Use a 50ohm resistor, I am sure if you can obtain one of these and somehow
> get a "spare" antenna you can remove the antenna bit from the spare, and
> solder in the resistor so that it "Shorts" the center pin to the ground
> brass sleeve. This way your wireless has a "Perfect match" and will not
> damage the wireless card..
>
> Do some googling on Dummy loads and you will understand then about 50ohm and
> 75ohm radio transmitters and how they are matched, a dummy load will not
> radiate, apart from miniscule ammounts. esp at 2.4ghz and will be a perfect
> match.
>
> Opinions by HubSwitch
> (Radio Amateur)

How about using a paper clip for a more permanent solution? :^)

--
Barry
Anonymous
a b F Wireless
July 21, 2004 3:20:08 PM

Archived from groups: alt.internet.wireless (More info?)

"Jeff Liebermann" <jeffl@comix.santa-cruz.ca.us> schreef in bericht
news:e22sf05a6muaikggm3rjodvj2nhd01i0rm@4ax.com...
> On 20 Jul 2004 12:57:19 -0700, jlarsen@fsu.edu (John Larsen) wrote:

> >Any suggestions on how to completly block a signal. I have a device

> What's a "device"? Is that like a wireless router or bridge? If so,
> just configure the MAC address filter to only accept connections from
> one MAC address. Make it one that will never be issued. The result
> is that nobody connects.

Good solution. Just mind the fact that if someone really wants to get into
your system, they'll just change their MAC adress (not easy to do, but
certainly possible).
Anonymous
a b F Wireless
July 21, 2004 3:20:09 PM

Archived from groups: alt.internet.wireless (More info?)

On Wed, 21 Jul 2004 11:20:08 +0200, "Rens Kempen"
<usenet@renskempen.SPAMBLOCK.nl> wrote:

>"Jeff Liebermann" <jeffl@comix.santa-cruz.ca.us> schreef in bericht
>news:e22sf05a6muaikggm3rjodvj2nhd01i0rm@4ax.com...
>> On 20 Jul 2004 12:57:19 -0700, jlarsen@fsu.edu (John Larsen) wrote:
>
>> >Any suggestions on how to completly block a signal. I have a device
>
>> What's a "device"? Is that like a wireless router or bridge? If so,
>> just configure the MAC address filter to only accept connections from
>> one MAC address. Make it one that will never be issued. The result
>> is that nobody connects.

>Good solution. Just mind the fact that if someone really wants to get into
>your system, they'll just change their MAC adress (not easy to do, but
>certainly possible).

The access point does NOT "advertise" or broadcast the available MAC
addresses that are allowed to connect. It advertises the SSID, it's
own BSID (MAC address), channel number, modulation method, max speed,
etc, but not the allowable MAC addresses. If someone wants in, they
would need some traffic to determine the sole acceptable MAC address,
and since there would be no traffic to sniff, it could not be
determined. No traffic means there's nothing to sniff.

One could mount a brute force attack by sequentially trying every
possible MAC address (4.3 billion). That would eventually [1] work,
but would then be faced with cracking the WEP key. Again, without any
traffic, the WEP key could not be determined by sniffing. If WEP is
deemed insufficient, one could be devious and use WPA pointing to a
non-existant RADIUS server, which would never authenticate anyone.

[1] I just did a very crude measurement on how long it takes for my
BEFW11S4 takes to respond to a failed association. It varies between
50msec and 150msec. I'll call it 100msec or 10 MAC addresses per
second. To try all 4.3billion MAC addresses would take 4,910 days
with a crude probability of hitting the correct MAC address in about
half that time.



--
Jeff Liebermann jeffl@comix.santa-cruz.ca.us
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558
July 21, 2004 7:17:13 PM

Archived from groups: alt.internet.wireless (More info?)

Actually, this is by far the best solution offered. The point is that if you
restrict to a randomly-chosen MAC address that you will never use, an
outside hacker has no way to know which address you are filtering on.
Excluding local and group bits, you have 2^46 ~= 64 * 10^12 possibilities, a
number vastly exceeding any hacker's ability to brute-force.

Of course, you can also simply configure WEP. Since the OP is not planning
to use the wireless portion of the network, there will be no wireless
traffic and therefore no clues to allow hackers to exploit statistical
weaknesses of WEP. They'd have to brute-force it, and with a keylength of
128 - 256, that's highly unlikely.

If you're really obsessive, do both. IMHO, either of these things is
preferable to yanking antennas and soldering on resistors.

"Rens Kempen" <usenet@renskempen.SPAMBLOCK.nl> wrote in message
news:cdlcg9$c8o$1@news1.tilbu1.nb.home.nl...
> "Jeff Liebermann" <jeffl@comix.santa-cruz.ca.us> schreef in bericht
> news:e22sf05a6muaikggm3rjodvj2nhd01i0rm@4ax.com...
> > On 20 Jul 2004 12:57:19 -0700, jlarsen@fsu.edu (John Larsen) wrote:
>
> > >Any suggestions on how to completly block a signal. I have a device
>
> > What's a "device"? Is that like a wireless router or bridge? If so,
> > just configure the MAC address filter to only accept connections from
> > one MAC address. Make it one that will never be issued. The result
> > is that nobody connects.
>
> Good solution. Just mind the fact that if someone really wants to get into
> your system, they'll just change their MAC adress (not easy to do, but
> certainly possible).
>
>
Anonymous
a b F Wireless
July 22, 2004 12:04:45 AM

Archived from groups: alt.internet.wireless (More info?)

osiris@deltaville.net (Michael Erskine) wrote in message news:<e59f93b2.0407202002.1e38ec11@posting.google.com>...
> jlarsen@fsu.edu (John Larsen) wrote in message news:<1b151b59.0407201157.7868bc61@posting.google.com>...
> > Any suggestions on how to completly block a signal. I have a device
> > that I wish to use its ethernet and turn off its wireless (leaving it
> > on leaves security problems) but there is no option in its
> > configuration to do this. I've removed the antenta and tried covering
> > the hole with aluminum wrap, but still got a signal from a good
> > distance. I need to have no signal from any distance (or atleast no
> > signal from 10 feet away seriously).
> >
> > Any suggestions.
>
> Yep, dummy loads. Get a of 50 ohm carbon resistors and remove the
> antenna and replace it with the 50 ohm resistor. Mind you ten feet is
> just this side of, how dumb is this desire?

Tried to resist posting exactly why I needed this. Basically I bought
a WPG54G (wireless presentation gateway) Anyways it definatly has
issues, guess I should have read the negative reviews before I bought.
When wired to a connection, or even connecting wirelessly to access
point then back to wired connection on WPG54G, it works great. When
directly connecting to it via wireless it works good too, but it
provides security problems if I allow to you see rest of network
through it, but I want users to be able to connect to internet and it
at same time. Seems as though wireless to access point then wired to
WPG54G would make sence but NOOOOO. Software that comes with it that
does the VPN stuff to send your screen image into the projector forces
you to switch your wireless connection to the projector (if it can
find it that is, if not it stays on your existing network). So thats
why I want to block it, and 10 feet because laptops would be atleast
10 feet away as its on the ceiling connected to projector in the
middle of a ring of tables.
!