Recently i discovered that my ISP hijacks my DNS queries and injects his own DNS servers even if in TP-Link router i enter specific DNS servers to use (Cloudflare IPV4&IPV6).

According to GDPR,  network architectures will need to deter DNS hijacking and the use of DNS for exfiltration. The main challenges here are related not to the hacktivists and malware seeking to vandalize the systems, but to sophisticated attackers who know which specific sets of data they aim to exfiltrate.

In my case ISP is the “sophisticated attacker”.

Since the enforcement of GDPR to ISPs meets various obstacles from them a solution was found for immediate use.

I switch my TP-Link router for an other manufacturer router that supports DNS over TLS at firmware level and the problem was solved. No more DNS hijacking and injecting from my ISP. My DNS queries remains my own in term of privacy and security.
It is vital, not even for security reason but also privacy (not to mention GDPR compliance) that DNS over TLS ability should be given top priority for TP-Links routers.