---
title: "mg_set_protocol_dns()"
decl_name: "mg_set_protocol_dns"
symbol_kind: "func"
signature: |
  void mg_set_protocol_dns(struct mg_connection *nc);
---

Attach built-in DNS event handler to the given listening connection.

DNS event handler parses incoming UDP packets, treating them as DNS
requests. If incoming packet gets successfully parsed by the DNS event
handler, a user event handler will receive `MG_DNS_REQUEST` event, with
`ev_data` pointing to the parsed `struct mg_dns_message`.

See
[captive_dns_server](https://github.com/cesanta/mongoose/tree/master/examples/captive_dns_server)
example on how to handle DNS request and send DNS reply.