So the web GUI within OPNsense only has input for up to 2 DNS servers. I have a tertiary DNS that I'd like to send out to all clients on my LAN but am unsure of how to go about it.
I found an older post that mentioned using hexadecimal numbers in "Additional Options" using "6" as the number and type "String", using a concatenated hex string for the 3 DNS IP's in the Value field, then leaving the DNS servers "blank" in the GUI. I've found that this doesn't work...after an ipconfig /renew on one of my Windows clients, the OPNsense router's IP is given out as the DNS server instead of the 3 IP's converted over to hex. Any additional suggestions? Thanks.