OPNsense handling DNS requests from clients when all DNS services are disabled

[dodgeboy]

If this is a standard setup for Multi-WAN, which is the guide(s) I followed when I originally configured it years ago, why is it causing this behavior?  I can consistently reproduce the behavior by enabling the gateway group on a rule, and it goes away when I remove it.  Is it a bug?

[dseven]

If this is a standard setup for Multi-WAN, which is the guide(s) I followed when I originally configured it years ago, why is it causing this behavior?  I can consistently reproduce the behavior by enabling the gateway group on a rule, and it goes away when I remove it.  Is it a bug?

Eric is saying that the standard setup for Multi-WAN includes the rule to explicitly NOT use a gateway for local DNS, which you were missing - step 5 here: https://docs.opnsense.org/manual/how-tos/multiwan.html#step-5-add-allow-rule-for-dns-traffic

Without that, any connection from your LAN will get sent to the gateway - even DNS directed to the firewall itself.

[dodgeboy]

Excellent!  Thank you for the clarification.  I saw step 5, but missed the explanation.  I think this finally solves it for me.  I appreciate everyone's help!