I am having a terrible problem on 1 of my 27 nodes. On Sunday I got complaints about packet loss and slow Speeds. I logged int he MK and did a scan and frequency test.. nothing showed out of the ordinary. I then noticed that when I stopped only about 4 out of 40 clients came back on. I looked at the noise and it is -102, and I just checked for interference and found none. So I checked the cable, antenna, and the db output of the SR2 and it was fine 24db.. I then changed the entire AP(mini-itx) with all new equip.. Same exact problem. Now here is where it gets interesting. I have a mixture of CPEs. I have CB3,dilberants, Tranzeos, and of course now I am only using RB133c. So I have about 5 133cs out there and the rest are mostly CB3s.
I found that If I pick the nosiest channel ( -88 ) and then disable and re-enable the wifi card a bunch of times.. every so often everybody comes on, and they works. The way I can tell is to be MAC pinging one of the Mikrotik 133c boards. I can tell when it *works* cause I get a 2ms ping time. If it doesn't work I get no clients and no pings. Sometime I see the Mikotik133c connect.. but pass no traffic and the ping fails.
I borrowed a full Spectrum Analyzer and did a sweep from 0-6000mhz and found no interference.
To further convince myself this is a broken CPE killing me. I logged into the 5 133c and changed the SSID on them, then I changed the SSID on the AP.. and those 5 MK CPES worked prefect every time. and no matter what channel I was on. When I switch back to the correct SSID to get all the rest of the clients on, I see the same problem. So it seems to me that some CPE has a bad association method, and if it does not associate correctly, it kills the AP.. if I disable/enable card I trick the CPE into trying over.. and if I do that enough.. the CPE finally connects, it stops killing the connection. The reason I have to be on the nosiest channel is because I believe the offending CPE has a weak signal, and by choosing a noisy channel , I lower it's overall affect and thus I am able to get some clients on..I did try blocking all CPEs on the access list and then only letting some on. but that does not work. The only thing I can make work every time is changing the SSID and having the few Mikrotiks only on the network, and that works perfect every time.
Maybe.. this is all a theory. I would love for someone to tell me I am wrong and what to do. It scares the hell out of me that a single CPE could take down the rest.