
RB serving as gateway for a hundred smartphone clients
RB is DNS/DHCP server
In few hours I end up with many hundreds DNS cache entries like these :

AP are WiFi routers indeed, and I continuously have dns queries from their ip address to RB in 5-10 pkt/sec rate
I’m not aware of wifi routers configuration , they get each a dhcp lease from RB
Is this normal behavior or something to be worried about ?