ACSP neighbor information

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I am trying to fine tune and optimize our RF environment.

I do a show acsp neighbor

I am just wondering what the refresh rate is, because I change a neighbor channel or power there does not seem to be any change to the neighbor information.

So just wondering how often this information is updated

I have looked through the CLI guide and I don't see anyway of clearing the ACSP neighbor information.

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Andrew MacTaggart, Champ

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Posted 4 years ago

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Andrew MacTaggart, Champ

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It took somewhere between 1 hour to 2

is there a way to force a refresh?

without a reboot or much disruption to clients

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Roberto Casula, Champ

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Hi Andrew,

As far as I am aware, after an initial "foreground scan" at bootup, for interfaces in access mode, the data collected for ACSP for "off-channel" channels (which includes the neighbour reports) is updated based on background scan (if enabled), so the speed of refresh is related to a number of factors such as:

1. The background scan interval (default 10 minutes)
2. The background scan settings (whether to proceed with the background a scan if there are clients connected etc.)

If you do a show log buff | include background you can see how those periodic scans are progressing.

My belief based on what I've seen (as it's documented anywhere I can find in any detail) is that the background scan scans one channel each scan cycle. That being the case, on the 2.4GHz radio, with the default settings, you could be waiting up to a couple of hours for the channel you're interested in to be scanned again, on the default interval of 10 minutes, which tallies with what you saw.

If you disable and re-enable scan ([no] radio profile xxx scan access), it's not clear whether it starts again at the lowest channel or just continues where it left off. The logs don't seem to give an indication of which channel is being scanned, just the fact that A channel is being scanned each time.

So you could reduce the scan interval (minimum 1 second), but bear in mind some clients - especially VoIP and older clients, or clients in a power-save state - might experience problems with background scanning due to missed packets (worst case dropped packets, for example if the AP misses a UAPSD trigger and exhausts its power save buffer). Hence the settings to skip scanning if there are clients/voice traffic/power save clients.

There are a lot of things like this where I'd love some more in-depth technical detail from Aerohive around the exact operation (and/or more useful logging information). It would make troubleshooting much less hit-and-miss.

Happy to be corrected on any of the above by somebody from Aerohive with more detailed knowledge!

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Eliu Rodriguez

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Great comment Robert. I hope that someone from Aerohive can answer soon or add something to this topic.