DNS forwardings entries lost after few days

I'm using OpenWrt 19.07.7 r11306-c4a6851c72.

DNS forwardings entries lost after few days. I must input manually with "vi /etc/config/dhcp" & restart dnsmasq

Anyone got this?

try it like this https://openwrt.org/docs/guide-user/base-system/dhcp_configuration#dhcp_options

option 6,

I want to block "3gppnetwork.org" access internet

I'm not familiar with the command line

for that, you need to use your own DNS, and have the clients use it.

DNS forwardings have nothing to do with blocking DNS names.

Another option might be the banIP package, it blocks by IP instead of DNS name.

Thank you for responding. Sorry for my English. Let me make it clear.

I use NextDNS on my router.

There are many queries that mess up the NextDNS log (about 40% of total daily hits). So i don't want that query sent to. is fake IP. My LAN use 172

I don't know why DNS forwardings entries lost after few days.

PS: China phone & access point flooded the dns server log.

If you use some external DNS, you won't be able to control the sites your clients surf to.
You could set up your own DNS, feeding of NextDNS, it'd let you control the DNS traffic
in your LAN.

If you're only interested in banning one specific site, I'd just stop the traffic from going
out to the specific IP(s) by setting up a rule in the firewall .... or installing BanIP.

Thank you very much.

I will try your advices.