Enable remote DNS over Wireguard VPN

Hi,

i want to run my Opal in a split tunnel configuration: Wireguard VPN for a transfer net, all other traffic shall be handled by the normal gateway (normal cable home router with IPv4/masquerading).

In the Wireguard transfer net i operate a DNS (bind). This is working. Wireguard is also working. The Opal basically is also working after i detected there is a “automatic router” mode.

But i dont seem to manage that the dns process on the Opal uses the remote DNS at least for forwarding specific addresses. The Wireguard configuration file provides the IP for the remote DNS and this is shown in the automatic DNS mode (but names are not resolved). If i manually use the remote DNS IP on a connected (LAN/Wifi) client, the name resolution works fine. It does not matter which DNS mode i try but i would like most the automatic mode where DHCP provides the Opal DNS and the Opal forwards name resolution requests for <mydomain.intern> to the remote DNS.

Can you advise what to do?

Hello,

Is the VPN policy mode set to auto detect(route)? If yes, this behavior might occur.
You can only set the custom DNS server in the DHCP server option 6 and distribute it to the clients.

In Luci > Network > LAN > Edit > DHCP server > Advanced settings, add DHCP-Options 6, [custom DNS IP]