DNS Filter

Envoy supports responding to DNS requests by configuring a UDP listener DNS Filter.

The DNS filter supports responding to forward queries for A and AAAA records. The answers are discovered from statically configured resources, clusters, or external DNS servers. The filter will return DNS responses up to to 512 bytes. If domains are configured with multiple addresses, or clusters with multiple endpoints, Envoy will return each discovered address up to the aforementioned size limit.