@AsafD 

If you do not want to accept the default DNS setting from your ISP, you can change that in two places:

1. in More/Internet Connection, you can change the DNS values for IPV4 and/or IPV6.  
2. in More/Advanced/DHCP server, you can change the DNS values distributed via DHCP.

Leaving (2) as default, I observe that the DHCP server of the Deco distributes, as first DNS server, the first DNS server set in (1) , and, as second DNS server, its own IP address.

  @AsafD 

Hi,

To set up DNS on Deco M3:

1. Open Deco app (v3.7.5).
2. Check 'More' → 'Advanced.'
3. If not found, try 'Internet' settings.
4. Access main Deco unit via browser if needed.
5. Look for DNS or WAN settings.
6. Enter DNS server addresses.
7. Save changes and reboot.

Best,
Alicek