DHCP stops working after installing DNS-over-HTTPS (DoH)

Installing and Using OpenWrt
1

Hello everyone,

I am using a Dynalink WRX36 router with OpenWrt installed. The device works flawlessly with all configurations set up, and I can use it as expected in a stable manner. However, I encounter a significant issue when I try to enable DNS-over-HTTPS (DoH).

After installing the necessary DoH package and configuring it, the router stops assigning DHCP leases to connected devices. As a result:

All connected devices lose their IP addresses.
Devices fail to reconnect to the network and have no access to the internet.

I have double-checked my DoH configuration and ensured that the package is installed correctly. Everything seems fine on the router's side, but as soon as DoH is enabled, DHCP functionality breaks completely.

Here are some additional details:

The DHCP server is enabled and works perfectly until DoH is activated.
Rebooting the router does not resolve the issue while DoH remains enabled.
Disabling or uninstalling the DoH package immediately restores DHCP functionality.

It seems there is some kind of conflict between the DoH package and the DHCP server, but I am unable to determine what might be causing this behavior.

I would appreciate any guidance on troubleshooting this issue. Has anyone else experienced a similar problem? If so, how did you resolve it?

Thank you in advance for your help!

2

dnsmasq is used for both DHCP and DNS.

if you stop it, and only use DoH proxy, you'll lose the DHCP.

use the DoH proxy as upstream resolver for dnsmasq, or disable the DNS in dnsmasq.

this is an user error, not an openwrt issue.

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3

Use https-dns-proxy instead. It requires no additional configuration and works with dnsmasq
first remove the previously installed DoH packages. then restart dnsmasq service. at this stage you should get access to internet. and then install the https-dns-proxy.

  1. opkg remove <previous-DoH-package>

( optionally you can then try autoremove to remove the dependencies)

  1. service dnsmasq restart

  2. opkg install https-dns-proxy

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4

Thank you for the suggestions provided earlier. I followed the steps and applied the recommended fixes, and they temporarily resolved the issue. However, the problem returns every time I reboot the router. After a reboot, the router again fails to assign DHCP addresses to connected devices, and I lose internet access on those devices.

To temporarily fix the issue, I have to repeat the same steps each time I reboot the router.

I am looking for a permanent solution to ensure that the https-dns-proxy and DHCP work seamlessly, even after a reboot. Any advice on how to make the configuration persistent would be greatly appreciated.

5

Can you post the output of
service
after an immediate reboot.

also the output of

logread |grep dnsmasq

and

logread | grep proxy

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