Multi-WAN 2 tier and Unbound DNS has DNS failure mode

[peb]

I have 2 WANs set up as tier 1 and 2, and I enabled Unbound DNS. Today the tier 1 WAN failed completely and tier 2 WAN took over. Pings of ip addrs and existing connections over tier 1 were working, but new DNS lookups did not.

I was able to get Unbound DNS working again by picking my tier 2 WAN only in "Outgoing Network Interfaces". When this was set to the recommended Any or if I checked both WANs, DNS did not work.

Is this a bug? I have Opnsense 19.1.4

I thought Unbound DNS would send requests over both WANs. It seems like the wrong approach to fail when I am using Multi-WAN. Should I not use Unbound DNS if I have Multi-WAN?

(Interesting observation: I often have partial failover of WAN due to high packet loss almost every day, but it took a rare complete failure to see this problem. I think Unbound DNS always uses the top tier.)

[mimugmail]

Seems you also need default gateway switching enabled

[peb]

I tested this:

    System: Settings: General: [ x ] Allow default gateway switching

and DNS was working after I unplugged my tier 1 WAN.

This should be mentioned in the how-to documentation for Multi-WAN.

[mimugmail]

https://github.com/opnsense/docs/pull/196

[mimugmail]

Seems you also need default gateway switching enabled

I am having the same problem and tried enabling this option. However its still not working. I can ping IP addresses from WebGUI using WAN 2 as interface however not resolve hostnames. DNS is failing at WAN 2

Then you have a different problem as author stated it works for him now. Maybe worth open a new thread