diff --git a/libraries/WiFi/examples/ETH_LAN8720_internal_clock/ETH_LAN8720_internal_clock.ino b/libraries/WiFi/examples/ETH_LAN8720_internal_clock/ETH_LAN8720_internal_clock.ino
new file mode 100644
index 00000000000..482ee8142f8
--- /dev/null
+++ b/libraries/WiFi/examples/ETH_LAN8720_internal_clock/ETH_LAN8720_internal_clock.ino
@@ -0,0 +1,100 @@
+/*
+    This sketch shows how to configure different external or internal clock sources for the Ethernet PHY
+*/
+
+#include <ETH.h>
+
+/* 
+   * ETH_CLOCK_GPIO0_IN   - default: external clock from crystal oscillator
+   * ETH_CLOCK_GPIO0_OUT  - 50MHz clock from internal APLL output on GPIO0 - possibly an inverter is needed for LAN8720
+   * ETH_CLOCK_GPIO16_OUT - 50MHz clock from internal APLL output on GPIO16 - possibly an inverter is needed for LAN8720
+   * ETH_CLOCK_GPIO17_OUT - 50MHz clock from internal APLL inverted output on GPIO17 - tested with LAN8720
+*/
+#define ETH_CLK_MODE    ETH_CLOCK_GPIO17_OUT
+
+// Pin# of the enable signal for the external crystal oscillator (-1 to disable for internal APLL source)
+#define ETH_POWER_PIN   -1
+
+// Type of the Ethernet PHY (LAN8720 or TLK110)
+#define ETH_TYPE        ETH_PHY_LAN8720
+
+// I²C-address of Ethernet PHY (0 or 1 for LAN8720, 31 for TLK110)
+#define ETH_ADDR        0
+
+// Pin# of the I²C clock signal for the Ethernet PHY
+#define ETH_MDC_PIN     15
+
+// Pin# of the I²C IO signal for the Ethernet PHY
+#define ETH_MDIO_PIN    2
+
+
+static bool eth_connected = false;
+
+void WiFiEvent(WiFiEvent_t event) {
+  switch (event) {
+    case SYSTEM_EVENT_ETH_START:
+      Serial.println("ETH Started");
+      //set eth hostname here
+      ETH.setHostname("esp32-ethernet");
+      break;
+    case SYSTEM_EVENT_ETH_CONNECTED:
+      Serial.println("ETH Connected");
+      break;
+    case SYSTEM_EVENT_ETH_GOT_IP:
+      Serial.print("ETH MAC: ");
+      Serial.print(ETH.macAddress());
+      Serial.print(", IPv4: ");
+      Serial.print(ETH.localIP());
+      if (ETH.fullDuplex()) {
+        Serial.print(", FULL_DUPLEX");
+      }
+      Serial.print(", ");
+      Serial.print(ETH.linkSpeed());
+      Serial.println("Mbps");
+      eth_connected = true;
+      break;
+    case SYSTEM_EVENT_ETH_DISCONNECTED:
+      Serial.println("ETH Disconnected");
+      eth_connected = false;
+      break;
+    case SYSTEM_EVENT_ETH_STOP:
+      Serial.println("ETH Stopped");
+      eth_connected = false;
+      break;
+    default:
+      break;
+  }
+}
+
+void testClient(const char * host, uint16_t port) {
+  Serial.print("\nconnecting to ");
+  Serial.println(host);
+
+  WiFiClient client;
+  if (!client.connect(host, port)) {
+    Serial.println("connection failed");
+    return;
+  }
+  client.printf("GET / HTTP/1.1\r\nHost: %s\r\n\r\n", host);
+  while (client.connected() && !client.available());
+  while (client.available()) {
+    Serial.write(client.read());
+  }
+
+  Serial.println("closing connection\n");
+  client.stop();
+}
+
+void setup() {
+  Serial.begin(115200);
+  WiFi.onEvent(WiFiEvent);
+  ETH.begin(ETH_ADDR, ETH_POWER_PIN, ETH_MDC_PIN, ETH_MDIO_PIN, ETH_TYPE, ETH_CLK_MODE);
+}
+
+
+void loop() {
+  if (eth_connected) {
+    testClient("google.com", 80);
+  }
+  delay(10000);
+}
diff --git a/libraries/WiFi/src/ETH.cpp b/libraries/WiFi/src/ETH.cpp
index 00481c2e1bc..cf53978e8f3 100644
--- a/libraries/WiFi/src/ETH.cpp
+++ b/libraries/WiFi/src/ETH.cpp
@@ -30,6 +30,7 @@ extern void tcpipInit();
 static int _eth_phy_mdc_pin = -1;
 static int _eth_phy_mdio_pin = -1;
 static int _eth_phy_power_pin = -1;
+static eth_clock_mode_t _eth_clk_mode = ETH_CLOCK_GPIO0_IN;
 static eth_phy_power_enable_func _eth_phy_power_enable_orig = NULL;
 
 static void _eth_phy_config_gpio(void)
@@ -56,7 +57,7 @@ ETHClass::ETHClass():initialized(false),started(false),staticIP(false)
 ETHClass::~ETHClass()
 {}
 
-bool ETHClass::begin(uint8_t phy_addr, int power, int mdc, int mdio, eth_phy_type_t type)
+bool ETHClass::begin(uint8_t phy_addr, int power, int mdc, int mdio, eth_phy_type_t type, eth_clock_mode_t clock_mode)
 {
     esp_err_t err;
     if(initialized){
@@ -84,6 +85,7 @@ bool ETHClass::begin(uint8_t phy_addr, int power, int mdc, int mdio, eth_phy_typ
     }
 
     eth_config.phy_addr = (eth_phy_base_t)phy_addr;
+    eth_config.clock_mode = clock_mode;
     eth_config.gpio_config = _eth_phy_config_gpio;
     eth_config.tcpip_input = tcpip_adapter_eth_input;
     if(_eth_phy_power_pin >= 0){
diff --git a/libraries/WiFi/src/ETH.h b/libraries/WiFi/src/ETH.h
index 95469f186b1..0bb70ffda5a 100644
--- a/libraries/WiFi/src/ETH.h
+++ b/libraries/WiFi/src/ETH.h
@@ -44,7 +44,11 @@
 #define ETH_PHY_MDIO 18
 #endif
 
-typedef enum { ETH_PHY_LAN8720, ETH_PHY_TLK110, ETH_PHY_MAX} eth_phy_type_t;
+#ifndef ETH_CLK_MODE
+#define ETH_CLK_MODE ETH_CLOCK_GPIO0_IN
+#endif
+
+typedef enum { ETH_PHY_LAN8720, ETH_PHY_TLK110, ETH_PHY_MAX } eth_phy_type_t;
 
 class ETHClass {
     private:
@@ -56,7 +60,7 @@ class ETHClass {
         ETHClass();
         ~ETHClass();
 
-        bool begin(uint8_t phy_addr=ETH_PHY_ADDR, int power=ETH_PHY_POWER, int mdc=ETH_PHY_MDC, int mdio=ETH_PHY_MDIO, eth_phy_type_t type=ETH_PHY_TYPE);
+        bool begin(uint8_t phy_addr=ETH_PHY_ADDR, int power=ETH_PHY_POWER, int mdc=ETH_PHY_MDC, int mdio=ETH_PHY_MDIO, eth_phy_type_t type=ETH_PHY_TYPE, eth_clock_mode_t clk_mode=ETH_CLK_MODE);
 
         // NOT WORKING YET!
         //bool config(IPAddress local_ip, IPAddress gateway, IPAddress subnet, IPAddress dns1 = (uint32_t)0x00000000, IPAddress dns2 = (uint32_t)0x00000000);