ESP32 Forum

Code: Select all

#include "esp_system.h"
#include "esp_netif.h"
#include "esp_eth.h"
#include "esp_log.h"
#include "esp_netif_dhcpc.h"

esp_eth_handle_t eth_handle = NULL;
esp_netif_t *eth_netif = NULL;

/* Function to get the default gateway MAC address */
void get_gateway_mac(void)
{
    esp_netif_ip_info_t ip_info;
    esp_netif_get_ip_info(eth_netif, &ip_info);
    /* Get the ARP table from the netif */
    arp_table_t *arp_table = esp_netif_get_arp_cache(eth_netif);
    /* Find the ARP entry with the gateway IP */
    arp_entry_t *arp_entry = arp_table_find(arp_table, &ip_info.gw);
    if (arp_entry != NULL) {
        ESP_LOGI(TAG, "Gateway MAC address: %02x:%02x:%02x:%02x:%02x:%02x",
                arp_entry->mac[0], arp_entry->mac[1], arp_entry->mac[2],
                arp_entry->mac[3], arp_entry->mac[4], arp_entry->mac[5]);
    } else {
        ESP_LOGW(TAG, "ARP entry not found for gateway IP");
    }
}

void app_main()
{
    /* Initialize the network interface */
    esp_netif_config_t netif_cfg = ESP_NETIF_DEFAULT_ETH();
    eth_netif = esp_netif_new(&netif_cfg);
    ESP_ERROR_CHECK(esp_eth_driver_install(&ETH_DRIVER_CONFIG, &eth_handle));
    ESP_ERROR_CHECK(esp_eth_start(eth_handle));
    ESP_ERROR_CHECK(esp_netif_set_default(eth_netif));

    /* Get the gateway MAC address */
    get_gateway_mac();
}

Code: Select all

#include <esp_eth.h>
#include <esp_eth_netif_glue.h>
#include <netif/etharp.h>

Code: Select all

struct eth_addr mac_addr;
ip4_addr_t ip_addr;
ip4addr_aton("192.168.1.1", &ip_addr);  // replace with your router's IP address
if (etharp_get_entry(&esp_netif_default, &ip_addr, &mac_addr) == ERR_OK) {
  Serial.print("Router MAC address: ");
  for (int i = 0; i < ETHARP_HWADDR_LEN; i++) {
    Serial.print(mac_addr.addr[i], HEX);
    if (i < ETHARP_HWADDR_LEN - 1) {
      Serial.print(":");
    }
  }
  Serial.println();
} else {
  Serial.println("Error retrieving MAC address");
}