RF interference cause loss of LAN connectivity on WAP11?

Sunday night, my Linksys WAP11 was working great! Monday morning, none
of our laptops could reach it. I also could not reach the config web
pages on the wired LAN. I ran the Linksys config utility, and it also
could not find the WAP11. I hauled the unit to work and plugged it
into the LAN there. It worked great! Hauled it home and it still would
not work (either wireless or LAN). Running the site survey utility on
one of the laptops, I found another new 802.11G network on the same
channel. It was running with no encryption, so I tried doing an ssh
login to my server through it. Worked fine! Looked at the server log
for the IP of the login and found it corresponds to a DSL from the
local phone company (not my DSL provider). So... figuring MAYBE this
is an RF interference problem, I pulled the antennae off the back of
the WAP11 and powered it up again. I was then able to reach the config
web pages and change the channel. Put the antennae back on, and all is
well.

So... can RF interference (especially 802.11G) tie up the processor in
the WAP11 so much that it won't even respond to http requests from the
LAN? That's my only explanation as to what's going on. Any other
ideas?

THANKS!

Harold

Were you broadcasting your SSID?
The zero conf wizard will attach to aps that are broadcasting the SSID and
avoid those that are not.
If you were attached to another network trying to attach to your AP which
could have a different IP then it wouldnt work

m2c.



"Harold Hallikainen" <(E-Mail Removed)> wrote in message
news:(E-Mail Removed) om...
> Sunday night, my Linksys WAP11 was working great! Monday morning, none
> of our laptops could reach it. I also could not reach the config web
> pages on the wired LAN. I ran the Linksys config utility, and it also
> could not find the WAP11. I hauled the unit to work and plugged it
> into the LAN there. It worked great! Hauled it home and it still would
> not work (either wireless or LAN). Running the site survey utility on
> one of the laptops, I found another new 802.11G network on the same
> channel. It was running with no encryption, so I tried doing an ssh
> login to my server through it. Worked fine! Looked at the server log
> for the IP of the login and found it corresponds to a DSL from the
> local phone company (not my DSL provider). So... figuring MAYBE this
> is an RF interference problem, I pulled the antennae off the back of
> the WAP11 and powered it up again. I was then able to reach the config
> web pages and change the channel. Put the antennae back on, and all is
> well.
>
> So... can RF interference (especially 802.11G) tie up the processor in
> the WAP11 so much that it won't even respond to http requests from the
> LAN? That's my only explanation as to what's going on. Any other
> ideas?
>
> THANKS!
>
> Harold

On 24 Nov 2004 10:09:20 -0800, (E-Mail Removed) (Harold
Hallikainen) wrote:

>Sunday night, my Linksys WAP11 was working great!

Which version WAP11? There are 5.

>So... figuring MAYBE this
>is an RF interference problem, I pulled the antennae off the back of
>the WAP11 and powered it up again. I was then able to reach the config
>web pages and change the channel. Put the antennae back on, and all is
>well.

Nice troubleshooting job. Did you try moving the WAP11 to a different
channel.

>So... can RF interference (especially 802.11G) tie up the processor in
>the WAP11 so much that it won't even respond to http requests from the
>LAN? That's my only explanation as to what's going on. Any other
>ideas?

Since you didn't mention the USB configuration port, I'll assume you
have the 2.2, 2.6 or 2.8 version.

802.11g traffic is treated by an 802.11b radio as interference if run
in the 802.11g only mode. Since you were able to detect the offending
access point, it is not running in 802.11g only mode.

I have no idea if wireless traffic or noise can busy out the WAP11
processor to that extent. I do know how to busy out any AP with
various probes, MAC address generators, and DoS attack generators.
However, I really doubt your neighbor is into such things. I would
guess(tm) that you should not be affected by "normal" 802.11g traffic.
To be sufficiently affected, they would need to be continuously
sending traffic, such as TIVO video wireless connection, file sharing,
or a major downloader. High traffic is the key.

I can sorta simulate your setup as I just "found" a WAP11 v1.1 (close
enough). However, it will have to wait until later next week.
Meanwhile, could you interrogate your neighbor and get the model
number of their wireless access point. If uncooperative, you can
extract it's MAC address, which should give me a clue as to the
manufactory and possibly the model. Ask about the type of traffic as
it would need to be continuous to do such damage.

Also, ask the neighbor a loaded question. "When the computers are
idle, is there any substantial LAN or wireless taffic visible as
continuous flashing lights on the modem or router?" If so, it's
probable they have a worm or trojaned computer.



--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558

Thanks for all the comments! The status page does not give the
revision of the hardware. The firmware revision is v2.05, Aug. 04,
2003.

Regarding the neighbors WLAN, over the air it's identified as a Belkin
something or another. It was running with no encryption, MAC
filtering, etc., so I was able to connect to it and use ssh to log
into my server. I then checked my server logs and found the IP address
of where the login came from. Did a host lookup of the IP address and
found it to be a Verizon DSL. Other than that, I don't know which
neighbor is running the network.

I was finally able to connect to the WAP11 over the wired network by
disconnecting the antennae from the WAP11. At least I think that's
what got it working. From the configuration web pages over the wired
LAN, I was then able to change the channel and get my wireless network
running again.

So, it seems strange that something on the RF would mess up the LAN
connection, but it just may be what happened.

Harold

On 27 Nov 2004 21:04:53 -0800, (E-Mail Removed) (Harold
Hallikainen) wrote:

>Thanks for all the comments! The status page does not give the
>revision of the hardware. The firmware revision is v2.05, Aug. 04,
>2003.

Well, it's usually on the serial number tag. Sometimes it's a
seperate sticker (that falls off). If it has a USB port on the back,
it's a 1.0 or 1.1. If no USB, it's 2.2, 2.6, or 2.8. Firmware
version 2.05 corresponds to the latest from hardware mutation v2.8.
http://www.linksys.com/download/firmware.asp?fwid=196

>Regarding the neighbors WLAN, over the air it's identified as a Belkin
>something or another. It was running with no encryption, MAC
>filtering, etc., so I was able to connect to it and use ssh to log
>into my server. I then checked my server logs and found the IP address
>of where the login came from. Did a host lookup of the IP address and
>found it to be a Verizon DSL. Other than that, I don't know which
>neighbor is running the network.

Nice of them to leave it wide open for you to use. What I was hopeing
to determine was if it was one of the new Super-G, Turbo-G, or Pre-N
wireless routers.

Connect to it again, and then run:
arp -a
on your computer. You'll see the IP address of the Belkin router
along with its MAC address. If not, ping the router once and it
should appear. The MAC address might tell me the manufacturer and
possibly the model number (if it's on a list).
http://hacks.oreilly.com/pub/h/826
http://www.coe.uky.edu/~stu/nic/nic.cfm
If you feel really ambitious, point your web browser at their access
point IP address. It probably doesn't have a password. As I vaguely
recall, some Belkins routers display an initial status page that does
not require a login. Anyway see if you can get the model number, or
2nd best, the MAC address.

>I was finally able to connect to the WAP11 over the wired network by
>disconnecting the antennae from the WAP11. At least I think that's
>what got it working. From the configuration web pages over the wired
>LAN, I was then able to change the channel and get my wireless network
>running again.

Well, it seems your analysis of the problem was correct, that 802.11g
traffic was killing your WAP11. The best I can do is try my WAP11
v1.1 under similar test conditions. However, it will have to wait as
I'm going to be rather busy starting Monday.

>So, it seems strange that something on the RF would mess up the LAN
>connection, but it just may be what happened.

Not so strange if it's what I'm guessing is the cause. My guess(tm)
is that an ordinary 802.11g access point would not cause this problem.
However, there's something about either a Super-G, Turbo-G, or Pre-N
access point that's causing havoc. All of these are 802.11b
compatible and should theoretically NOT cause any such interference,
but that's based on manufacturers tests, not those of customers. What
you're seeing may not be something they've test for. Dunno.


--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 AE6KS 831-336-2558

Thanks again for all the ideas. Since my WLAN is now working, I'll
probably just leave it alone and not dig further. It was such a
strange problem, I just had to ask!

I'd be interested in hearing if anyone else can duplicate the problem.

THANKS!

Harold

Another follow - up on the issue. Last weekend I got a WAP54G and had
the same problem. I THINK I've tracked it down to a temperature
problem! The WAP was located on a top shelf in an upstairs room that
gets rather warm. The WAP54G didn't work there, but when I hauled it to
work and plugged it into the network there, it worked fine! Trying to
figure out what's different between work and home, I was left with the
RF environment, the LAN configuration and traffic, and temperature
(it's always cold at work). So, exhausting everything else, I stuck the
WAP54G in the refrigerator at home for 30 minutes, then took it back
upstairs, but put it on the floor instead of the top shelf. It worked
great! So, all my previous writings about RF interference MAY have been
totally wrong. It appears the WAP series is a bit sensitive to
temperature. On the same shelf I have a Linksys 8 port router, a SIP
phone adapter, the DSL modem, and a few other things. I'm going to put
the WAP54G on a lower shelf and try to cool off that room!
Thanks to the group for the ideas on the problem!

Harold

On 12/22/04 4:46 PM, (E-Mail Removed) wrote:
> Another follow - up on the issue. Last weekend I got a WAP54G and had
> the same problem. I THINK I've tracked it down to a temperature
> problem!

Does it really run that hot?

I am planning to put a LinkSys WRT54GS wireless router into a sealed box
and your post is not very encouraging. :-)

Thanks.

Following up further... I'm STILL having loss of LAN connectivity with
the WAP54G. If I just wait a while, it comes back. If I power cycle it,
it generally comes back. Has anyone else had this happen? Any ideas?
THANKS!

Harold

(E-Mail Removed) wrote:
> Following up further... I'm STILL having loss of LAN connectivity with
> the WAP54G. If I just wait a while, it comes back. If I power cycle
> it, it generally comes back. Has anyone else had this happen? Any
> ideas? THANKS!
>
> Harold

Yup.. had the same problem.. Goto the Linksys website, and download and
install the firmware upgrade for that model.... Turns out that even though I
bought it after the upgrade date, it was already shipped to the store with
the older version of the firmware. Worked like a charm for me.