guest network with DNS issue

[mauro]

I followed the online documentation about how to create a guest network skipping the captive portal setup.

The FW rules are as shown on the documentation

I have a machine in the guest network and realized couldn't get online. after few checks I realized it is a problem of DNS.

I tried:

Code Select Expand

ping facebook.com
with 100% package lost

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ping 8.8.8.8
with no issue

UnboundDNS is enable with access to any interfaces

My temporary workaround has been to pass an external DNS server with the DHCP setting.

Can someone help to understand where is the problem?
There is no DENY msg in the FW log

thanks