First i would like to mention i have 1 pihole connected to my OpenWrt router and everything is working great, pihole is doing its thing.
Now i want to redirect/hijack all DNS queries to pihole, and i follow this link: (https://jeff.vtkellers.com/posts/technology/force-all-dns-queries-through-pihole-with-openwrt/) but it just didn't work. I have forwarded port 53, 853, 8053 and 5353... none worked.
I would like to mention that i have tried setting my phone (connected to the same OpenWrt router) with a public DNS (188.8.131.52), and i get "no network" alert... but immediately got network again after using my pihole DNS agaib. However, when "no network" was showing, i could not access any websites at all, except WhatsApp and Telegram (both works)!
I even tried to put () as regex blacklist in pihole, and everything was blocked.... except WhatsApp and Telegram! Now how can i tell these apps to use my pihole? Are there any settings i need to? Searching the web i found lots of iptable configurations, but the new OpenWrt don't support that anymore (or i have no idea how to).
I also found this page (https://openwrt.org/docs/guide-user/firewall/fw3_configurations/intercept_dns) but i have no idea which files to type those comments in... clearly the "Web Interface Instructions" did not work cause the guide above used that method...
Please help me as i bought an OpenWrt router specifically for blocking WhatsApp cause pihole alone was not enough.