Understanding ISP DNS Hijacking and Why DoH is Essential

In many regions, local Internet Service Providers (ISPs) implement web filtering by intercepting unencrypted DNS queries on port 53. When a user tries to access a restricted domain, the ISP's DNS resolver replies with a falsified IP address, redirecting the user to a block page.
This practice, essentially a form of sanctioned DNS hijacking, raises significant privacy concerns. It means ISPs can monitor, log, and control exactly which domains their users are requesting.
The Solution: DNS over HTTPS (DoH)
To mitigate this privacy vulnerability, the tech community has rapidly adopted DNS over HTTPS (DoH). DoH encrypts DNS queries by wrapping them in HTTPS traffic (port 443). Because the queries are encrypted and mixed with regular web traffic, ISPs can no longer intercept or easily analyze the DNS requests.
Using a privacy-respecting, low-latency public DNS resolver like Cloudflare (1.1.1.1) or Google Public DNS (8.8.8.8) is the most effective way to bypass ISP-level DNS filtering without the overhead and potential security risks of free VPNs.
Implementation Guide
Configuring Private DNS or DoH is now natively supported on modern operating systems, including Android 9+ and recent iOS versions.
If you are looking for a practical, step-by-step tutorial on how to implement this on mobile devices to circumvent connectivity issues, I highly recommend reading this detailed guide: Cara Ganti DNS Cloudflare di Android dan iOS (Anti-Blokir) on the Agendadu Tech Blog.
Conclusion
Securing your DNS queries is no longer just for developers or privacy extremists; it is a fundamental step for everyday secure digital navigation. By switching to DoH, you ensure that your browsing habits remain private and your access remains unrestricted by local network manipulations.