Dear all,
I have mikrotik groove A52Hpn AP, and linksys WRT54GL like Client bridged - (Wireless) connected to Groove ap,
At linksys i have connected by cable PC, my pc MAC Is: 94:DE:80:XX:XX:F2
at groove log i see all the time listing:
wlan1: data from unknown device 94:DE:80:XX:XX:F2 sent deauth
wlan1: data from unknown device 94:DE:80:XX:XX:F2 sent deauth
wlan1: data from unknown device 94:DE:80:XX:XX:F2 sent deauth
etc…
How to solve this ?
Thank you
Looks like interference or bad wireless communication.
when registered, what’s the CCQ of the lynksys?
Look for it at Wireless > Registration table, double click on the Linksys (it will show your PC MAC as it’s in bridged client mode) and go to the Signal tab.
this is signal connection at linksys router
CCQ should be higher for reliable wireless, 85-100%. Looks like interference, play with your channel selection.
an
/interface wireless spectral-history range=2.4ghz wlan1
will show you which channels are more suitable (black or blue) in your environment.
this is printscreen
Repeat the command with range=2400-2480, leave it running several minutes.
after 3-4 min
Try with frequency 2422, looks like the most clear part of your spectrum.
i changed but nothing doed 
agai continue loging sent deauth.
What happened to the CCQ? did it get better? try 2217 and 2427 frequencies.
Does that Groove have other wireless clients? Do they get better CCQs?
If that’s not the case, check the groove N connector is making good mating with the antenna N connector. Are you using the stock 6dBi one? Or a third party one?
at 2437 and othe chanels is same near 65 to 95 , at the groove also i have other clients and the antenna is 18dbi 360 degree and groove is directli connected to the antenna.
a try to change all channels but nothing.
some other idea ?
Do the other clients have good stable CCQs? If so, the problem could be on the Linksys.
i don``t think so the linksys is problem, because other clients on linksys not have sent deauth, i have also connected on linksys by other switch wired, devices, other devices function is normal, just one computer have deauth.
Not idea what can be ?
I had the same issue a ubiquity device as a station connecting to a Mikrotik AP ,to solve this I disabled WDS on the station side. 
Solutions is:
If you bridged Eth and Wlan interface together, check in IP->Address that you assign local ip address on bridge interface, not only on Eth interface…this was solve my problem. 
Good luck!