TP-Link has released new firmware that fixes this issue (including a list of affected products).

TP-Link has released new firmware for many of their range extenders that address this issue. The update changes the behavior from NTP+DNS requests on the public internet to ICMP pings on the local...

It affects at least these TP-Link products/firmware versions: RE450(AU)_V2_170626 [*]RE500(EU)_V1_170420 [*]RE650(EU)_V1_170524 [*]TL-WA850RE(US)_V4_170109 [*]TL-WA855RE(EU)_V1_160414

I investigated this issue and wrote up my findings in detail for anyone who is interested. Current versions of TP-Link repeater firmware use 715,4 MB per month just to show us “Internet Status:...