I run the Deco in Router mode.

In the Deco settings of the DHCP Server, I did not specify primary and secondary DNS.

I observe that Deco distributes, via DHCP, as address for the secondary DNS server, the local IP of the Deco.

This occurs independently of the specification of DNS servers In the Deco settings of the Internet Connection (left to default or not).

Seeing that, I assumed that the Deco was able to act as an intermediate DNS server.  However, by testing from a Windows computer using nslookup, I realise that the Deco does not respond to DNS queries.

I believe the Deco should not, by default, send via DHCP its own local IP address as secondary DNS server.