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I set up a small wireless grid, 9 access points spread throughout a school and nearly every day I have trouble of somesort, where the entire unit (specifically the ethernet side) fails and my only recourse is to reboot the AP(s).

They are all broadcasting the same SSID using wpa /psk encryption. In the beginning I had the channel/frequency set to 'auto', but after some research I changed it to alternating between channels 1,6,and 11. This hasn't helped at all.

If you're setting up a grid 'on the cheap' without any central managed switch, should I program all APs to broadcast on the same frequency? Should I have some APs broadcast on half or reduced power?

As for the device information, they are all Netgear wg 102 access points with the latest firmware (one of my first troubleshooting efforts).

Thanks for any advice,
~ Aaron

Aaron503 Escribi?3:

I set up a small wireless grid, 9 access points spread throughout a school and nearly every day I have trouble of somesort, where the entire unit (specifically the ethernet side) fails and my only recourse is to reboot the AP(s).


--- Can you provide more specific information regrading the failure. For example, can the wireless client still auth/ass to the wireless, receiving dhcp, but cant pass traffic on the wired side?


They are all broadcasting the same SSID using wpa /psk encryption. In the beginning I had the channel/frequency set to 'auto', but after some research I changed it to alternating between channels 1,6,and 11. This hasn't helped at all.

--- Correct, channels 1,6,11 are correct. Standard states 25 MHz between center channels.

If you're setting up a grid 'on the cheap' without any central managed switch, should I program all APs to broadcast on the same frequency?

-- no, its always best to stick with the 3 channel 1,6,11. But this raises the question, what area are you covering with a total of 9 aps...

Should I have some APs broadcast on half or reduced power?

As for the device information, they are all Netgear wg 102 access points with the latest firmware (one of my first troubleshooting efforts).



Thanks for any advice,
~ Aaron

Wireless Failure Information:
Wireless signal is still broadcasting, yet clients cannot get a dhcp address. Eventually defaulting to the 169.254.x.x. I'm not 100% sure, but the failure seems to be almost like a 'system lock' and the ethernet port shuts down.

The AP is no longer pingable when the failure occurs. (This is how I can check it with a nagios box).

As for the coverage, its a roughly 20 classroom elementary school. I have strong signal in every classroom / office. When everything is working, I can walk around and maintain at minimum a 36mbps connection rating.

Again the only recourse I have is a simple reboot on the access point and everything generally comes back.

Is this house wide or is it just a few APs?

All of them basically. Every day I'll come in and find say numbers: 1,3,5,8 APs as 'down'... then the next day or so I'll usually find numbers: 2,4,6, etc.

Doesn't seem to have much rhyme or reason.

In fact, here's the other part that will blow your mind. I have another school with 12 APs doing the exact same thing. However, I have a third school with 15 access points with the channel mode set to auto and everything works well. It is mind-boggling. Same Netgear wg102

I have not worked with your exact AP in question before, but lets go through some basic discovery:

* Are there any logs on the APs
* Are you seeing any interface issues/errors
* Does your duplex match on the switch and AP port(half/full)
* When the AP goes 'down', you confirmed you can still get on the wireless (L2) but cant pass traffic, correct ... very important

I just enabled snmp and syslog on an access point to go to a my machine. So far nothing unusual has been generated. Just mac addresses of a laptop that has authenticated to it.

If there is anything interesting, I will definitely post it.

Switch ports are all defaulted to Auto negotiate... although I could force them to be full duplex on the setting.

I can virtually guarantee that it isn't a problem with the frequency. The fact that L2 on the wired side is what is failing shows us that.

I'd be a nickel that the problem is the AP itself. Excessive traffic, weird data etc can lock up an inexpensive AP. Heck, in labs I have seen "good" AP's lock up.

To be honest, you are in an enterprise environment and if at all possible, you should get enterprise AP's. At such a low quantity you will spend some more money, but not budget breaking.

If that isn't possible, wireless and wired packet capture are the next steps.

GT

I agree its not in the spectrum. Sounds like something on the wired. Did you check the switch ports for errors? Also, for giggles can you set the clients to a static address and take DHCP out of the mix... What is dishing out your DHCP btw?

I don't think it is a DHCP problem since he says that he come is and it says that the AP's are down. I was guessing (maybe incorrectly) that it was some type of management server telling him that they were responding. If I'm off base, then I agree set it to static and see what floats.

GT