Second and third NTP servers are not working

[szerwi]

Hardware:

Board: ESP32 Dev Module
Core Installation version: 1.0.5
IDE name: Arduino IDE
Flash Frequency: 80Mhz
PSRAM enabled: no
Upload Speed: 115200
Computer OS: Windows 10

Description:

I am using SimpleTime example. I have added second and third NTP server, but when I change first NTP server's address to wrong one, it cannot obtain time. configTzTime() and configTime() are not using second and third NTP servers.

Sketch: (leave the backquotes for code formatting)

#include <WiFi.h>
#include "time.h"

const char* ssid       = "xxx";
const char* password   = "xxx";

const char* ntpServer = "wrong.ntp.org";
const char* ntpServer2 = "pl.pool.ntp.org";
const char* ntpServer3 = "3.pl.pool.ntp.org";
const long  gmtOffset_sec = 3600;
const int   daylightOffset_sec = 3600;

void printLocalTime()
{
  struct tm timeinfo;
  if(!getLocalTime(&timeinfo)){
    Serial.println("Failed to obtain time");
    return;
  }
  Serial.println(&timeinfo, "%A, %B %d %Y %H:%M:%S");
}

void setup()
{
  Serial.begin(115200);
  
  Serial.printf("Connecting to %s ", ssid);
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
      delay(500);
      Serial.print(".");
  }
  Serial.println(" CONNECTED");
  
  configTzTime("CET-1CEST,M3.5.0,M10.5.0/3", ntpServer, ntpServer2, ntpServer3);
  //configTime(gmtOffset_sec, daylightOffset_sec, ntpServer, ntpServer2, ntpServer3); //same situation
  printLocalTime();

  WiFi.disconnect(true);
  WiFi.mode(WIFI_OFF);
}

void loop()
{
  delay(1000);
  printLocalTime();
}

Debug Messages:

Connecting to xxx [D][WiFiGeneric.cpp:374] _eventCallback(): Event: 0 - WIFI_READY
[D][WiFiGeneric.cpp:374] _eventCallback(): Event: 2 - STA_START
[D][WiFiGeneric.cpp:374] _eventCallback(): Event: 4 - STA_CONNECTED
[D][WiFiGeneric.cpp:374] _eventCallback(): Event: 7 - STA_GOT_IP
[D][WiFiGeneric.cpp:419] _eventCallback(): STA IP: 192.168.1.113, MASK: 255.255.255.0, GW: 192.168.1.1
. CONNECTED
Failed to obtain time
[D][WiFiGeneric.cpp:374] _eventCallback(): Event: 5 - STA_DISCONNECTED
[D][WiFiGeneric.cpp:374] _eventCallback(): Event: 3 - STA_STOP
Failed to obtain time
Failed to obtain time
Failed to obtain time
Failed to obtain time

[lbernstone]

Support for multiple ntp servers is not compiled into the arduino libraries. You would need to roll your own to get this.
https://github.com/espressif/arduino-esp32/blob/1.0.5/tools/sdk/include/lwip/lwip/apps/sntp_opts.h#L58 or https://github.com/espressif/arduino-esp32/blob/1.0.5/tools/sdk/include/lwip/lwip/opt.h#L887

[szerwi]

@lbernstone Thanks for the information. Do you plan to add it in the future?

[lbernstone]

That comes from upstream (lwip), but I seriously doubt it. It is a pretty good chunk of memory that most people won't use. Using a pool address from ntp.org is pretty reliable.

[fthiebolt]

Hello, i was facing the same issue ... moreover, i really need NTP FROM DHCP answer (yes our university is blocking outgoing ntp packets !!)
After struggling for a while, i was able to recompile lwip with support for 3 NTP servers along with NTP from DHCP answer:

git clone -b v3.3.5 --recursive https://github.com/espressif/esp-idf.git esp-idf-v3.3.5
export IDF_PATH=${HOME}/esp-idf-v3.3.5
cd esp-idf-v3.3.5
export IDF_TARGET="esp32"
./install.sh
. ./export.sh
cd examples/get-started/blink
cp ~/.arduino15/packages/esp32/hardware/esp32/1.0.6/tools/sdk/sdkconfig sdkconfig
make menuconfig
    <load sdkconfig>
vim ${IDF_PATH}/components/lwip/lwip/src/include/lwip/opt.h
    880 #define LWIP_DHCP_GET_NTP_SRV           1
    887 #define LWIP_DHCP_MAX_NTP_SERVERS       3
idf.py build

Then you need to backport those mods to your arduino release:

apply same opt.h mods to:
    ~/.arduino15/packages/esp32/hardware/esp32/1.0.6/tools/sdk/include/lwip/lwip/opt.h
cp build/esp-idf/lwip/liblwip.a ~/.arduino15/packages/esp32/hardware/esp32/1.0.6/tools/sdk/li

need to mention i'm using 1.0.6 esp32 arduino so i chose esp-idf 3.3.5

Of course, i would have loved a much more simpler way to achieve this simple lwip mod (fairly simple on esp8266-arduino)
Hope this helps

[Rotzbua]

I think it should be mentioned in the examples like:

arduino-esp32/libraries/HTTPClient/examples/BasicHttpsClient/BasicHttpsClient.ino

Line 59 in 7856de7

configTime(0, 0, "pool.ntp.org", "time.nist.gov");

Also if possible a compile warning or runtime log would be useful.

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[STALE_SET] This issue has been automatically marked as stale because it has not had recent activity. It will be closed in 14 days if no further activity occurs. Thank you for your contributions.

[vortigont]

Ugh! This really took me a while to find out why the heck a function with 3 ntp server params just silently ignores two of it. At least a note in source comments would be nice.

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[stale]

[STALE_SET] This issue has been automatically marked as stale because it has not had recent activity. It will be closed in 14 days if no further activity occurs. Thank you for your contributions.

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