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WiFi.config() allows you to configure a static IP address as well as change the DNS, gateway, and subnet addresses on the WiFi shield.

Unlike WiFi.begin() which automatically configures the WiFi shield to use DHCP, WiFi.config() allows you to manually set the network address of the shield.

Calling WiFi.config() before WiFi.begin() forces begin() to configure the WiFi shield with the network addresses specified in config().

You can call WiFi.config() after WiFi.begin(), but the shield will initialize with begin() in the default DHCP mode. Once the config() method is called, it will change the network address as requested.


WiFi.config(ip, dns);
WiFi.config(ip, dns, gateway);
WiFi.config(ip, dns, gateway, subnet);


ip: the IP address of the device (array of 4 bytes)

dns: the address for a DNS server.

gateway: the IP address of the network gateway (array of 4 bytes). optional: defaults to the device IP address with the last octet set to 1

subnet: the subnet mask of the network (array of 4 bytes). optional: defaults to




This example shows how to set the static IP address,, of the LAN network to the WiFi shield:

#include <SPI.h>
#include <WiFi.h>

// the IP address for the shield:
IPAddress ip(192, 168, 0, 177);    

char ssid[] = "yourNetwork";    // your network SSID (name)
char pass[] = "secretPassword"; // your network password (use for WPA, or use as key for WEP)

int status = WL_IDLE_STATUS;

void setup()
  // Initialize serial and wait for port to open:
  while (!Serial) {
    ; // wait for serial port to connect. Needed for Leonardo only

  // check for the presence of the shield:
  if (WiFi.status() == WL_NO_SHIELD) {
    Serial.println("WiFi shield not present");
    while(true);  // don't continue


  // attempt to connect to Wifi network:
  while ( status != WL_CONNECTED) {
    Serial.print("Attempting to connect to SSID: ");
    // Connect to WPA/WPA2 network. Change this line if using open or WEP network:    
    status = WiFi.begin(ssid, pass);

    // wait 10 seconds for connection:

  // print your WiFi shield's IP address:
  Serial.print("IP Address: ");

void loop () {}
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