Can't ping self.

[SteveRMann]

If I don't call ping(), the ESP responds to ICMP ping requests from other devices on the local network. If I call ping(), the ESP cannot be pinged.

My test code:

`#define SKETCH "pingTest"
#define VERSION "1.00" // Four characters

/*
This program is a test of the ping function
*/

//-------------------------
#include <ESP8266Ping.h> //Includes ESP8266WiWi.h
#include <Kaywinnet.h> // WiFi credentials

char pingIP[20]; // IP that we're going to ping.

//****************************** SERIAL **************************
void beginSerial() {
Serial.begin(115200);
delay(1000);
Serial.println();
Serial.println(SKETCH);
Serial.println(VERSION);
Serial.println();
}

//****************************** WiFi **************************
void setup_wifi() {
Serial.println();
Serial.println("Connecting to ");
Serial.println(MY_SSID);

//WiFi.hostname(SKETCH);
WiFi.begin(MY_SSID, MY_PASSWORD);
while (WiFi.status() != WL_CONNECTED) {
delay(500);
Serial.print(WiFi.status());
Serial.print(" ");
}

Serial.println("\nWiFi connected, ");
Serial.print("MAC Address: ");
Serial.println(WiFi.macAddress());
Serial.print("IP address: ");
Serial.println(WiFi.localIP());
Serial.print("Hostname: ");
Serial.println(WiFi.hostname().c_str());
Serial.print(F("Default Gateway: "));
Serial.println(WiFi.gatewayIP().toString());
Serial.print(F("Subnet Mask: "));
Serial.println(WiFi.subnetMask());
}

//****************************** PING **************************

void pingit() {
Serial.print(pingIP);
Serial.print(F(": "));
if (Ping.ping(pingIP)) { // Ping
Serial.println("OK");
} else {
Serial.println("Fail");
}
// yield(); // Reset the WDT on the ESP8266
}

//****************************** SETUP **************************
void setup() {
beginSerial();
setup_wifi();
}

//****************************** LOOP **************************
void loop() {
strcpy(pingIP, "192.168.1.1");
pingit();
strcpy(pingIP, "192.168.1.57");
pingit();
strcpy(pingIP, "192.168.1.124");
pingit();
strcpy(pingIP, "192.168.1.183");
pingit();
strcpy(pingIP, "127.0.0.1");
pingit();

Serial.println(F("---------------"));
delay(1000);
}
`