Qcawifi-scanner: Can it be disabled for good?

Access Points
,
1

I use my Alta Route10 and AP6-Pro at home as our general-use prosumer router and access point setup. I also have my homelab connected to the system and I’m happy with it. However, I’ve come across one snag that is starting to become infuriating enough that I’m considering replacing my gear.

Despite having manual channels set up, not using DFS frequencies for 5GHz and disabling any kind of channel scanning feature in the Alta controller UI, I am experiencing occasional interruptions to wifi service due to randomized rogue AP scans.

Specifically, myself and my partner use wireless VR headsets that take advantage of the AP6-Pro’s reliable throughput to stream high bandwidth (80Mbit/s per stream) HEVC/AV1 video with absolute minimal latency. When the scanning takes place, it manifests itself as five short interruptions to the VR streams, after which there is an added delay that does not recover until all the VR gear is restarted. This ruins the immersive experience and becomes more infuriating as it is unpredictable and difficult to prevent.

Because I live in a rural area and don’t really have to worry about rogue APs, I routinely SSH into the AP6-Pro, run “killall qcawifi-scanner” and then “rm /lib/sh/qcawifi-scanner” to get rid of it, but it comes back like a fungus, sometimes when rebooting, and always whenever there is a firmware update, which is quite frequently. I disabled automatic firmware updates only to find that they were happening anyway.

I’ve tried adding commands to /cfg/post-cfg.sh to remove the offending scripts but this doesn’t help. My post-cfg.sh in both my Route10 and AP6-Pro look like this, so maybe I’m doing something incorrectly:

#!/bin/sh
#this overwrites https-dns-proxy's default config with only the DNS services I like to use, instead of adding google DNS and OpenDNS without my consent
cp /home/root/https-dns-proxy /etc/config/
service https-dns-proxy restart
#this prevents the random rogue AP and channel scans
killall qcawifi-scanner
rm /lib/sh/qcawifi-scanner
killall acsd
rm /usr/sbin/acsd

Yeah - I’m not happy with the forcing of DNS servers on this equipment’s DNS relay either, with no option in the controller UI to make this permanent. But that’s another topic.

What can I do to prevent qcawifi-scanner from returning once and for all? If this is not an option, I’m thinking of jumping ship.

2

You will lose 11k neighbor reports for seamless roaming if disabling qcawifi-scanner, but if you still really want to disable it, I don’t see why your script wouldn’t work. Are you still seeing qcawifi-scanner running even after deleting the script itself?

3

I have just the one AP, so no seamless roaming needed right now. The qcawifi-scanner script returns after a reboot or firmware update.

4

Yes, the file will return after reboot, but /cfg/post-cfg.sh will run after every configuration (including the configuration right at boot), so I would check that your script runs successfully when running it manually; then it should run fine at boot (after configuration).

2 Likes
5

Just to cover all the bases, has the post-cfg.sh file been set to be executable? I know I’ve overlooked that myself in the past :sweat_smile: Should just need to run chmod +x post-cfg.sh from the terminal to make that happen.

3 Likes
6

Yeah, looks like the script wasn’t set as executable. Running it manually after that to test it - this worked!

Now just have to see if it all stays after a reboot or update…

1 Like
7

Awesome! If it runs manually then to my knowledge, it should run anytime the AP is rebooted or refreshes its config. Fingers crossed! :crossed_fingers:

1 Like