I have replaced an old Juniper NetScreen device with an ASA. The ASA is connected to an ADSL modem and gets its IP via PPPoE. There are no issues with that. Unfortunately, it uses the ISP's DNS servers by default. On the old NetScreen device, I was able to use public DNS servers, e.g. 1.1.1.1 or 8.8.8.8.
This did however require a command to make it permanent, because otherwise it would revert back to the ISP's DNS server after a reboot. That command was set PPPoE DHCP-nochange
I think.
Is there a way to achieve the same on the ASA?