No Internet with R7800 and bridged modem

Hello,

we had a power outage and suddenly my router (r7800) wouldn't connect to the modem anymore.

I've reset the modem to router mode and also installed the latest OpenWrt firmware from hnyman on my R7800. Everything is vanilla/untouched and it's working fine so far.

I always had my modem in bridge mode to avoid problems because I was using dnsmasq etc. to have better privacy.

Now after switching the modem to bridge mode, the internet connection drops. When I am connecting directly to the modem via LAN from my PC, internet is available.

I've already added a new interface "modem" following the steps here: https://ciphermenial.github.io/access-your-modem-through-openwrt-router/

After that I have access to the menu of the modem via 192.168.100.1 (this is the default address after switching to bridge mode).

I am sure I have somehow to tell OpenWrt that there is a bridged modem but I've forgotten how I have done it last year and can't figure it out. I have no idea why the connection failed after the power outage. ...seems that the modem got a new IP/Gateway and the router couldn't connect anymore.

Please help, I know there is someone out there that know how it is done.
As said I am sure I have to change the interface somehow and add a firewall rule.
The WAN and WAN6 interface are in "DHCP Client"-Mode, I think that needs to be changed...

Any help is much appreciated.

Regards,
elexir

Maybe your isp uses static ip or pppoe? Try to check out the wan setup in your modem while in router mode. Perhaps the isp pushed a new configuration on the modem that got applied when the modem booted. If your concern is privacy, consider dns over tls or setting up a recursive dns on your router.

Thank you!

It seems that I just had to retstart the interfaces a few times to catch up the new modem.

Now what is the actual best setup for DNS? I had a DNS resolver that changed all the time randomly... can't remember what I've used but the packages were already installed in hnymans firmware afaik.

it was some v2 version of dnssec, dnsmasq or anything like that. I want it to be as secure as possible. Let's see what is the best right now.

[OpenWrt Wiki] DoT with Dnsmasq and Stubby