DNS (overview)
Leng works by proxying your DNS requests to an upstream DNS server, and returning a useless response when the request is for a blocked domain.
Blocked domains are those that appear on a blocklist (downloaded at startup). You can see which blocklists are enabled by default and how to change them in Configuration.
Additionally, you can also configure custom responses for specific domains, indepenently of the blocklists. See more in Custom DNS.
sequenceDiagram
User --> Leng:
Online Blocklists -->> Leng: Download lists
Note over Online Blocklists,Leng: At startup
User->> +Leng: A google.com
Leng ->> Upstream DNS: A gogle.com
Upstream DNS ->> Leng: google.com IN A 234.213.532.12
Leng ->> -User: google.com IN A 234.213.532.12
User ->> +Leng: A adservice.google.com
Leng ->> -User: adservice.google.com IN A 0.0.0.0