This what I saw today setting up a pop and adding 3 cpes to the pop.
Ap is MT133 2.9.43 board with Compex wlm54g card
cpes are MT133c 2.9.43 board with same Compex card

When settting the setting the channel in 2.4 with 5mhz settings on all equipment AP and cpes. When scanning for the Ap with the cpe it shows up on 3 channels this was with all 3 cpes I ran a scan with. When I place everything in the 10mhz setting everything was ok.

Has anyone else seen this?

bump to the top.

Come on anybody?

That's a common problem when you have a really good signal and your using 5/10mhz channels on Mikrotik 2.9. On 5mhz channels you will see ghost AP's every 20mhz and on 10mhz channels you will see a ghost ap every 40mhz above and below the real channel.

When I was at the Orlando MUM I asked everyone about this problem and the only answer I seemed to get was that it was something in the atheros driver or atheros chipset when operating in 5 and 10mhz modes..

I guess it was the driver b/c it has been fixed in the 3.0 beta's..

-Gerard

I have actually had the problem where a client associated to one of the ghost APs. It was a VERY strong signal (perhaps -38 or so) in 2.3, and the client associated to the first ghost signal rather than the main channel. Throughput was garbage of course!!

Part of this is the problem with older cards (CM9 for example) listening on a 20Mhz channel rather than a narrow channel (R52) I think.

Solution was to put only the main channel into the "scan list". You have to be careful changing a channel once you do this tho, because your clients won't associate to anything not in the scan list.

George

ghmorris,

It happens on all of the atheros cards. When I was at MUM I showed several people from Mikrotik the problem using the RB153's with R52's they gave to us in class.. It does the same thing on XR2's also.. I even borrowed an oscilloscope from one of the vendors there to show Mike from Ubiquiti the problem and to see if it was actually transmitting on those ghost frequencies. The scope didn't show anything being transmitted on the ghost frequencies so it is something inside the Atheros chip.

-Gerard

Gerard, I thought it was a receive-side issue. Hadn't realized it was on the transmit side.

Thanks for the info!

George

Thanks for the info, I thought may be a bug. I wonder if this will get a fix.

It has been fixed or at least worked around in 3.0 beta's.. I doubt we will see a fix for the 2.9 series though..

We used the scope to confirm that it was NOT on the transmit side.

-Gerard