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We have a ptmp 802.11a wlan using 2 patch antennas at each site and an omni at the root site. The 2 remote sites are probably a 1/4 mile away and have about 10 degrees of seperation when you are looking from the roof of the root site. 1 of the sites is a bit further away (200 ft or so) than the other one. We are experiencing disconnections which dont last long but we are doing vioce over the links and obviously the links drop. I just disabled one of the radios but the deauthentications continue. I have changed the channel on all the radios as well with the same results.

Here are the log entries on the root radio.
Interface Dot11Radio0, Deauthenticating Station 0019.5635.12f3 Reason: Previous authentication no longer valid

Any ideas?

What authentication mechanism are you using between the bridges? PSK or 802.1X/EAP?

Have you done a protocol capture with something like OmniPeek, AirMagnet, CommView for WiFi, AirDefense Mobile, etc looking for deauthentication frames?

Have you done a spectrum analysis looking for RF interference across the UNII bands?

Are all of the bridges made by the same manufacturer?

Have you done a signal strength test (and calculated your fade margin) to make sure your signal strength is good to go?

Do you have anything in the Fresnel Zone? Have you calculated the size of the FZ?

These are the first things to address, and then after all of that, you'll have info to take it further.

Hope this helps...and welcome to the forum!

Devinator

devinator Escribi?3:

What authentication mechanism are you using between the bridges? PSK or 802.1X/EAP?

PSK

Have you done a protocol capture with something like OmniPeek, AirMagnet, CommView for WiFi, AirDefense Mobile, etc looking for deauthentication frames?

Nope, my PDA w/ airmagnet went south and I need to find a replacement. I should have included the entire log set entries for the drops. It appears that the max retries gets exceeded the the root deauthenticates the remote bridge.

Interface Dot11Radio0, Station Riskbridge 0019.5635.12f3 Associated KEY_MGMT[WPA PSK]
Apr 26 17:02:57 Information Interface Dot11Radio0, Deauthenticating Station 0019.5635.12f3 Reason: Previous authentication no longer valid
Apr 26 17:02:57 Warning Packet to client 0019.5635.12f3 reached max retries, removing the client

Have you done a spectrum analysis looking for RF interference across the UNII bands?

The only thing I did was do a carrier check to make sure I had the best channel selected.

Are all of the bridges made by the same manufacturer?
Yep, they all all Cisco.

Have you done a signal strength test (and calculated your fade margin) to make sure your signal strength is good to go?

I was getting -72dbm on the root but I didnt do the original install and dont have the specifics.

Do you have anything in the Fresnel Zone? Have you calculated the size of the FZ?

I havent but there is no obstructions. The remote sites are 3 story bldg's and the root is 10 stories.

These are the first things to address, and then after all of that, you'll have info to take it further.

So it looks like I need to do a lot more troubleshooting before I can solve this one.

Hope this helps...and welcome to the forum!
Thanks for your suggestions.

Devinator