topic Re: show acsp neighbor returns nothing in 5ghz band in Aerohive Migrated Content

show acsp neighbor returns nothing in 5ghz band

tobias_protz — Thu, 26 Sep 2019 20:56:12 GMT

When sending the command "show acsp neighbor" to our AP250 access points, some return absolutely nothing in the 5ghz band, i.e. on their wifi1 interface - even though the interface is up and running on a completely normal frequency band, unhindered by anything nearby.

At least SOME clients or the nearest access point should show up I assume?

Does anyone have any idea how this can happen?

Re: show acsp neighbor returns nothing in 5ghz band

samantha_lynn — Thu, 26 Sep 2019 21:53:36 GMT

That likely means we aren't getting background scans through on that interface. If you run the command "show int wifi1" and look for BGSCANs, you should be able to see how many scans have been requested, successful, and missed for that interface.

You can adjust the background scan settings in the Radio profile to allow or block scans when you have clients connected, when you have clients in a power save move, and/or when you have voice traffic on the VLAN. I'd recommend enabling background scans for when you have clients connect and clients in power save move, and leave them disabled when there is voice traffic to avoid interrupting the VOIP packets.

Re: show acsp neighbor returns nothing in 5ghz band

tobias_protz — Thu, 26 Sep 2019 22:05:19 GMT

Thanks sam, I get the following result on the affected APs:

BGSCAN allow=enabled; BGSCAN during voice=disabled; BGSCAN interval=10 minutes;

BGSCAN with client=enabled; BGSCAN with PS client=disabled;

Number of BGSCAN=0; Number of BGSCAN requested=0; Number of BGSCAN missed=0;

Seems they do not scan at all on that interface, correct? The AP has been up for 17 days since the last reset, I would assume that it would've performed some scans during that time.

Re: show acsp neighbor returns nothing in 5ghz band

ashley_finch — Thu, 26 Sep 2019 22:18:55 GMT

Is the AP on a DFS(UNII-2 Extended) channel?

Re: show acsp neighbor returns nothing in 5ghz band

samantha_lynn — Thu, 26 Sep 2019 22:42:01 GMT

Ashley has a good point about DFS channels, and I would just like to add on to that, you may have clients in power save mode on your network which would prevent those scans with your current settings. I'd recommend enabling background scans when clients are in power save mode within your Radio profile, and to make sure you aren't on a DFS channel.

Re: show acsp neighbor returns nothing in 5ghz band

tobias_protz — Fri, 27 Sep 2019 13:31:12 GMT

Hello Ashley, hello Sam,

no, the APs are notall on the affected channels (some are).

I tried to set everything to manual yesterday (transmission power, channels) in order to get a stable config running, since we have a lot of interference problems (busy neighbourhood, lots of companies with powerful wifi nearby, we can even receive the wifi signals from stopped cars four levels below - seems like almost every manufacturer has its own wifi hotspot onboard these days). So I wanted at least our own APs to run as interference free as possible, since that did not work when they were allowed to set their channel and power themselves.

What I found though was that the APs did not adhere to the power limits set in their respective radio profile, neither do they accept the power settings I put in manually on the interface settings page (HM NG on premise, current version, all APs are AP250 running 10.0r7a )

p.ex. I set the limit for 5ghz to 17db in the profile, set the AP to 16db, it still stays at 20db.

Or: I set the limit for 2.4 to 3db, set the AP to 5db - it is running at 3db.

Can you explain this behaviour to me? Is there a bug in the current firmware?

Re: show acsp neighbor returns nothing in 5ghz band

samantha_lynn — Fri, 27 Sep 2019 19:53:33 GMT

The power being lower than you've set may be due to the difference between real power and EIRP power settings, but the power being higher than you've set it sounds like a bug. We'd need a case so we can gather some data to determine if it is a problem, but there aren't any known issues that I'm aware of currently that would cause that.

Re: show acsp neighbor returns nothing in 5ghz band

tobias_protz — Fri, 27 Sep 2019 20:00:23 GMT

I never saw someting like this either, so I conducted an experiment: Since I had to change some settings at a different location, I checked the APs there. They are running on different configs altogether, but their power settings, which were also fine-tuned by hand a few weeks ago, were also off the values set in the configs (again, a lot of them were higher).

So I did a full update on all of them and reverted them to 10.0R5, the version they had when the settings were changed.

After a reboot, they had different power settings - even higher now!

Even stranger, one AP currently has the 2.4ghz setting 2db higher than what I set in its individual configuration, but the 5ghz setting is 6db lower (both according to the monitor->devices view of HMNG).

I agree, this is very strange, and I have no idea what could cause this. When I initially set them to fixed power settings, they changed to them quite fast.

I also switched off the "client transmission power control" on both interfaces. (it was active at the remote location, but already disabled at our main site). No change.

I now fear that our HiveManager might somehow be defective, which would be bad, since we are rolling out 14 new APs in two months.

Re: show acsp neighbor returns nothing in 5ghz band

samantha_lynn — Fri, 27 Sep 2019 20:22:23 GMT

In that case I would suggest opening a case even more so we can get things stabilized before your new deployment.