ESP32 Forum

Posted: **Mon Nov 01, 2021 1:25 pm**

Hey,

I work on a software for ESP32 and use Ethernet kit A ver1.1.
When I use wifi STA and connect to my router, the software taken from the SNTP example provided with ESP-IDF (v4.4) works well.
However, when I use ethernet, the time is unable to synchronize. In this case, wifi STA is not configured.
In both cases I am working with static IPs. I configured DNS server to 8.8.8.8.
I tested that ethernet is configured properly and works in a way, that I am able to display my website loaded from ethernet IP address on my local network.

Please, do you have any guiding advice, why SNTP might not work via ethernet?

Thank you,
Jakub

Posted: **Thu Nov 04, 2021 10:42 am**

I found out that DNS setup is missing in my ethernet configuration, therefore it is unable to connect to the NTP server. When I provide direct IP address, it works. As a solution, I will soon provide command which sets the DNS for ethernet here.

Posted: **Mon Nov 08, 2021 11:22 am**

Here is the code snippet as promissed including DNS setup:

Code: Select all

esp_netif_dhcpc_stop(eth_netif);
esp_netif_ip_info_t info_t;
esp_netif_dns_info_t dns_info;
memset(&info_t, 0, sizeof(esp_netif_ip_info_t));
inet_pton(AF_INET, Configuration.staticip_eth, &info_t.ip);
inet_pton(AF_INET, Configuration.gateway_eth, &info_t.gw);
inet_pton(AF_INET, Configuration.subnetmask_eth, &info_t.netmask);
inet_pton(AF_INET, Configuration.dnsserver_eth, &dns_info.ip);
esp_netif_set_ip_info(eth_netif, &info_t);
esp_netif_set_dns_info(eth_netif, ESP_NETIF_DNS_MAIN, &dns_info);

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