Edit: doh, SwimmingPool noted this three weeks ago in another thread!
Does anyone have some data with an estimate of “how many computers / devices / whatever per capita” for different countries?
Also, this seems to suggest that doing away with the explicit country zones and just have DNS direct traffic appropriately might be a good idea (as came up about a year ago with regards to Snapchat).
TP-Link has made available new firmware updates for most models that resolves the issue. The update changes their internet connectivity testing from NTP requests against hardcoded addresses including NTP pool servers to ICMP requests against the local network gateway.
Notably, these devices don’t have auto-update, the manual check-for-update button in their web interface always reports that the software is up-to-date, and TP-Link doesn’t make the latest firmware versions available through their websites in all countries. E.g. updates for the NTP issue isn’t available for most models on TP-Link’s US website.
In other words, these devices are very unlikely to ever receive any updates that fixes this issue.
Fukuoka University had to kill its ntp server for being DDoSed by TP-Link and so many other devices… (below slides in Japanese)