STM32F429 not sending UDP on Multicast address (LwIP+FreeRTOS)

[BCall.1]

I m using LwIP+FreeRTOS (STM32Cube FW library for STM32f4xx 1.25.0).

I use the Ethernet to send TCP and UDP packets. Everything works fine: I have HTTP working, I can join Multicast groups (IGMP), I can send UDP packets on regular addresses.

But I can't send UDP packets on a multicast address. IGMP membership queries are fine but no UDP communication.

I traced it back down to the DMA transfer where I wasn't able to find anything wrong but the packet is never sent according to Wireshark from another machine.

Is there a specific setting to enable that or I am missing something ?

NB : The code is based on the demo project from the library with the IGMP settings advised on this support forum.

[JongOk Baek]

Dear, BCall.1,

Did you solve the problem.

I have a same problem.

--- < source code > ---

netbuf_alloc(tx_buf, len);

pbuf_take(tx_buf->p, (const void *)ptr, len);

err = netconn_sendto(conn, tx_buf, (const ip_addr_t *)&dstIP, dstPORT); // Destination : 239.192.0.2, Port 60002

----------------------------------

return value is ERR_OK.

but, data output is nothing.

At the same time, it transmits UDP,, it is output normally. (Destination : 192.168.10.10, Port 5100)

Please, let me know the your status!

Best regards,