getHostByName always failing to find a valid ip

Question

I'm using an arduino Uno and a CC3000 wifi shield. I installed Adafruit library in arduino to get access to Wifi network. I'm currently trying to run some samples that comes with the library. It successfully connects to Wifi network and returns

IP Addr: 192.168.137.101
Netmask: 255.255.255.0
Gateway: 192.168.137.10
DHCPsrv: 0.0.0.0
DNSserv: 8.8.8.8
localhost -> 172.217.22.46

Pinging 172.217.22.46...0 replies

But when it tries to connects to a remote service like "www.adafruit.com" or "www.google.com" it assigns ip to 0 which means the host ip unknown. My wifi-hotspot is capable of providing internet connection. Can anyone please tell me what can I do to access remote web site through Wifi from this configuration. Setup method of one of the sample codes that I tried is mentioned below.

void setup(void)
{
  Serial.begin(115200);
  Serial.println(F("Hello, CC3000!\n")); 

  displayDriverMode();
  Serial.print("Free RAM: "); Serial.println(getFreeRam(), DEC);

  /* Initialise the module */
  Serial.println(F("\nInitialising the CC3000 ..."));
  if (!cc3000.begin())
  {
    Serial.println(F("Unable to initialise the CC3000! Check your wiring?"));
    while(1);
  }


  uint16_t firmware = checkFirmwareVersion();
  if (firmware < 0x113) {
    Serial.println(F("Wrong firmware version!"));
    for(;;);
  } 

  displayMACAddress();

  /* Optional: Get the SSID list (not available in 'tiny' mode) */
#ifndef CC3000_TINY_DRIVER
  listSSIDResults();
#endif

  /* Delete any old connection data on the module */
  Serial.println(F("\nDeleting old connection profiles"));
  if (!cc3000.deleteProfiles()) {
    Serial.println(F("Failed!"));
    while(1);
  }


  char *ssid = WLAN_SSID;             /* Max 32 chars */
  Serial.print(F("\nAttempting to connect to ")); Serial.println(ssid);

  if (!cc3000.connectToAP(WLAN_SSID, WLAN_PASS, WLAN_SECURITY)) {
    Serial.println(F("Failed!"));
    while(1);
  }

  Serial.println(F("Connected!"));

  /* Wait for DHCP to complete */
  Serial.println(F("Request DHCP"));
  while (!cc3000.checkDHCP())
  {
    delay(100); // ToDo: Insert a DHCP timeout!
  }  

  while (! displayConnectionDetails()) {
    delay(1000);
  }

#ifndef CC3000_TINY_DRIVER
  /* Try looking up www.adafruit.com */
  uint32_t ip = 0;
  Serial.print(F("www.adafruit.com -> "));
  while  (ip  ==  0)  {
    if  (!  cc3000.getHostByName("www.adafruit.com", &ip))  {
      Serial.println(F("Couldn't resolve!"));
    }
    delay(500);
  }  
  cc3000.printIPdotsRev(ip);
  Serial.print(F("\n\rPinging ")); cc3000.printIPdotsRev(ip); Serial.print("...");  
  uint8_t replies = cc3000.ping(ip, 5);
  Serial.print(replies); Serial.println(F(" replies"));
  if (replies)
    Serial.println(F("Ping successful!"));
#endif
  Serial.println(F("\n\nClosing the connection"));
  cc3000.disconnect();
}

Answer 1

My CC3000 wifi shield was not working correctly. So I replaced wifi shield with a new one and solved the problem. It is very hard to identify a hardware fault when it is partially working. It seems that CC3000 connecting to the WIFI network. That confuses me. But when I read about the problem and tried replacing with a new board which was successful. By the way I learnt that this same problem can be occur when you are using a public wifi connection (example- University Wifi Connection). This question is a good source that answers the 2nd kind of problem.