Skip to main content
Associate II
May 13, 2026
Solved

STM32H743 Ethernet FreeRTOS LwIP Ping Problem

  • May 13, 2026
  • 7 replies
  • 311 views

Hi.

I'm trying a simple ping application with my board that contains the H743 microcontroller. I am following the instructions in Adam Berlinger's example. But I can't get ping. I connect my computer to my board via ethernet switch. My computer's IP is 192.168.2.5. But it can't reach to my board. When I try to send UDP packet, I can see the Ip adresses of target and destination(via WireShark software). But I can't see the "Hello UDP message!\n\r". IPs are manually setted. H7 board and computer connected via ethernet switch hub. I added a breakpoint to "void ETH_IRQHandler(void)". After the initial power-on, the system reaches the breakpoint twice even when there is no ping command on the Ethernet port. But when i send ping commands, nothing happens. I can reset LAN8742A PHY via GPIO. 

 /* Initialize all configured peripherals */
 MX_GPIO_Init();
 /* USER CODE BEGIN 2 */
 HAL_GPIO_WritePin(ETH_RESET_GPIO_Port, ETH_RESET_Pin, GPIO_PIN_RESET);
 HAL_Delay(50);
 HAL_GPIO_WritePin(ETH_RESET_GPIO_Port, ETH_RESET_Pin, GPIO_PIN_SET);
 HAL_Delay(100);
 /* USER CODE END 2 */

 

STM32CubeIDE

Version: 1.19.0

My configuration:

MPU1.jpg

MPU2.jpg

 

eth.jpg

Flash_ld.jpg

LwIP_GeneralSettings.jpg

LwIP_KeyOptions.jpg

FreeRTOS_Task.jpg

PS C:\Users> ping -S 192.168.2.5 192.168.2.10

Pinging 192.168.2.10 from 192.168.2.5 with 32 bytes of data:
Reply from 192.168.2.5: Destination host unreachable.
Reply from 192.168.2.5: Destination host unreachable.
Reply from 192.168.2.5: Destination host unreachable.
Reply from 192.168.2.5: Destination host unreachable.

Ping statistics for 192.168.2.10:
Packets: Sent = 4, Received = 4, Lost = 0 (0% loss),
PS C:\Users>
Best answer by Muharrem

I changed my hardware and the problem solved. Topic can be closed.

7 replies

MuharremAuthor
Associate II
May 13, 2026

I changed attached project

MuharremAuthorBest answer
Associate II
May 13, 2026

I changed my hardware and the problem solved. Topic can be closed.

Andrew Neil
Super User
May 13, 2026

@Muharrem  For the benefit of future readers who may find this while trying to solve a similar problem, it would be helpful if you would say what was wrong with your hardware, and how you changed it to fix the problem.

A complex system that works is invariably found to have evolved from a simple system that worked.A complex system designed from scratch never works and cannot be patched up to make it work.
MuharremAuthor
Associate II
May 23, 2026

I have two hardware. One of them had solder issue. So i tried other one and it worked. The problem wasn't exactly spesific. I could see the PHY chip's REF_CLK. I could see the UDP package's IP adres but i can't see the data of package. They were all 00. I resolder the MCU of the faulty board over and over again. And then faulty card started to work correctly

Associate II
August 17, 2026

Hii , I am using an STM32H750I-DK Discovery board with LAN8742 PHY, MII mode, FreeRTOS and LwIP.

Ethernet works initially: the STM32 IP appears in arp -a and I can ping it. After some time, the ARP entry disappears and ping gives Request timed out or Destination host unreachable.

I have already checked the IP configuration, MII configuration, PHY link, DMA, MPU/cache, and tried disabling RTP traffic, but the issue still occurs.

What could cause the STM32H750 Ethernet connection to stop responding to ARP and ping after working normally for some time? What should I check next?

Pavel A.
August 19, 2026

> What could cause the STM32H750 Ethernet connection to stop responding 

Does your firmware crash or hang? Even if not - there are some known issues with the ETH driver.

Please start a new question because the original one has been resolved.

 

Associate II
August 20, 2026

This problem has been resolved; the issue was with the memory mapping.