OpenVPN through Express DNS leaking

Hello world,

On the router I am replacing(Gl.iNet Slate), using Express servers, I had pretty poor performance but I never had any DNS links.

I just got an rPi4 working with the snapshot images, LuCi installed, and OpenVPN connected. It's performance is doubled(~11Mbps on the old one and now ~25Mbps) but I'm finding I'm getting a lot more DNS leaks.

I've come a long way just by figuring out how to get the rPi4 working but I feel my understanding of DNS & DHCP is lacking.

Would an experienced user know some configuration options I should set on OpenWRT to prevent this?

I found this suggestion in the documentation for DHCP configs: nmcli connection modify OVPN_CON ipv4.dns-priority "-50" ipv6.dns-priority "-50"

But it doesn't run return nmcli: not found and I can't seem to install it.

Edit: Well I did something that worked and I'd like to know what it was if someone knows.

  1. I went to LuCi > Network > DHCP & DNS > Resolv & Hosts Files: & checked the ignore resolve file box at the recommendation of this forum poster: DNS leak with OpenVPN

  2. From that same posts suggestion I added the list server fields

  3. LuCi > Network > interfaces: Selected it on the LAN interface and under use custom dns servers I filled in the same addresses as above.

  4. LuCi > Network > DHCP & DNS > DNS Forwardings: and then again inputed the same addresses.

In all 3 spots where I listed DNS providers the addresses were '', '', & ''

It seems excessive and redundant to assign the same addresses in 3 different places so what's exactly the difference here? I assume 1 instance sets the list server lines I added in /etc/configure/dhcp but then what would be the other one?

No more leaks!