Why is the radio 1 transmitting power with 0 dBm, even when the radio 1 is on and a channel is selected. (AP3825i-1)

  • 16 November 2018
  • 7 replies

Userlevel 1
We have a V2110 Medium running with Software:, after a few hours a lot of 3825i-1 (30 out of 80) starting transmitting power with 0 dBm!. And the clients can't see the emitted SSID anymore. We use all channels on Radio 1 (5GHz) and the selection is auto. You have to turn Radio 1 off and on to get back the power. The country code is correct and the license is valid. That's all a little bit miserable. Any suggestion how to solve the problem? Green IT? :-)

7 replies

Userlevel 1
Is there a neighbouring AP on the same 5GHz channel causing this one to ‘back off’ and drop power down? Anything in the controller or individual AP logs? Any logs mentioning RADAR being detected on the same 5GHz channel? Does your channel plan allow to move to non DFS if there is mention of RADAR? Personally I’d prefer to have the APs hard coded for both power and channels based on the initial physical site survey results.
Userlevel 1
The 5Ghz channels of the neighbours are all different, we check this with the floorplans in netsight, you can get a fast overview. Radar interference is not seen in this case. And it doesn't matter whether it's a non-DFS or a DFS channel. The APs doesn't log anything when they stop to "transmit" with 0 dBm. As far as you can see in the Identifi log of the APs.
Userlevel 7
How often does it happen... is it hours after the reboot,
Please post a screenshot of the AP radio#1 settings.

You'd check the detailed log on the AP ....
ssh to the AP
cd /tmp/log
cat ap.log

If it happens very often I'd try the folllowing with 2 different APs...
- factory reset a AP and sync again for a fresh start
- change the country to Austria
Userlevel 1
After the reboot it takes about 10 to 12 hours until it happens again. Maybe because there is no MU anymore.

To get the ap.log is not a problem, but to understand it and to know for what I'm looking is a Little bit tough.

a) I factory reset an AP 3825i and synced it again

b) I changed the country code of another AP 3825i to Austria

I'm looking forward for the results.
Userlevel 2
We had a similar problem with a deployment of AP3825e's. The APs would freeze up and stop transmitting. The power would drop to zero and the SSID would disappear. A reboot would bring them back for awhile but then they would freeze up again.

GTAC recommended to remove Radio Management 11k support from the VNSs that were working on the APs.
We did this and the problem did not recur.
Userlevel 1
Thank your for your suggestion,

but we don't have these feature on.

Userlevel 1
Here are my results from the last few days:
a) I factory reset an AP 3825i and synced it again
b) I changed the country code of another AP 3825i from Germany to Austria.

24 hours later the AP from a) and b) were still transmitting with more than 0 dBm.

Both solutions seem to work. So I had to facory reset about 26 APs, or take a another "Country Code".
I was not realy amused about both slolutions. Should I take cholera or black death?

I decided to have a look for a newer version and I found version
I installed the version on Saturday 11/17/2018 at 5pm.
And now 36 hours later still all APs are tranmitting power with more than 0 dBm.

Some background information: One week ago we made the version upgrade from to to Now with version everything seems to be fine.

Not clear what realy caused the problem, maybe the upgrade form 09.21 to 10.31. Now that's something for the experts. 🙂