Re: AP1200 losing radio frequency

simonthompson · ‎10-25-2004

Hi,

Has anybody experienced the problem of an access point not sending out its radio frequency? The hard wired network has not shown any problems and access to them via telnet and http is good. The access point has not shown any error messages in the log.

When trying to connect a client device to the access point, there was no rf from the access point. The config (ios) of the access point shows the rf interface as enabled and working. Upon rebooting the access point, it shows that the rf interface is now disabled - still with no error messages or logs.

We suspect that there might have been a spanning tree loop on the network although none of the typical symptoms of a spanning tree loop were present.

Does the aironet switch off the rf if it detects a spanning tree loop? If so, how can I verify it?

Thanks,

Simon

scottmac · ‎10-25-2004

How did you determine that there was no emission from the AP?

If you turned off the SSID broadcast, the clients will not automatically see the AP, you must specifically set them up to look for, associate, and authenticate to the specific AP/SSID.

Scott

simonthompson · ‎10-25-2004

I had a laptop with a configured radio card in it that had worked to the AP previously. We also used Netstumbler to sniff for the rf, but it showed nothing.

This was an existing, working installation that suddenly just stopped working. The funny thing was that when we unplugged the Ethernet from the AP, we got rf again.

Thanks,

Simon

dixho · ‎10-26-2004

Please do a show ip interface brief and find out the status of the dot11 radio interface. If you do a show controller dot 0 or show controller dot 1, you will find out he transmit power and the channel where the AP is on.

simonthompson · ‎10-26-2004

The problem suddenly occured on 8 Access Points at the same time. We suspect that it was due to a spanning tree problem, but would like clarity on why the APs shut the rf. If we unplugged the Ethernet, the rf came back, but as soon as the Ethernet was plugged in again, we lost the rf.

Is there something in the ios that causes the rf to be disabled if the AP detects a spanning tree loop?

scottmac · ‎10-26-2004

It sounds like you have the AP set for "Repeater" mode.

With "repeater mode" the ethernet connection is not allowed.

(it should just ignore the ethernet though, not shut down the radio).

Curious.

Scott

dixho · ‎10-26-2004

I think that repeater does the other way around. If a repeater associates to an AP, it shuts down its fast ethernet interface.