AVR Ethernet DNS example: hostname => IP

arduino-avr-ethernet-dns-resolve.ino

#include <SPI.h>
#include <Dns.h>
#include <Ethernet.h>

uint8_t mac[6];

void setup() {
  Serial.begin(115200);
  Serial.println(F("System initialization start..."));

  Ethernet.init(10);
  mac[0] = 0xDE;
  mac[1] = 0xAD;
  mac[2] = 0xBE;
  mac[3] = 0xEF;
  mac[4] = 0xFE;
  mac[5] = 0xED;
  Ethernet.begin(mac);

  if (Ethernet.hardwareStatus() == EthernetNoHardware) {
    Serial.println(F("Ethernet shield was not found. Sorry, can't run without hardware. :(\n"));
    return;
  }

  Serial.println(F("System initialization done"));


  Serial.println("Start DNS request...");
  DNSClient dns;
  IPAddress ip;
  
  dns.begin(Ethernet.dnsServerIP());
  if(dns.getHostByName("google.com", ip) == 1) {
    Serial.print(F("IP: "));
    Serial.println(ip);
  } else {
    Serial.print(F("dns lookup failed"));
  }

  Serial.println("End DNS request...");
}

void loop() {

}