Udp multicast address discarded on LS1028 switch port

[xinliwang]

Hi, @yipingwang 

I have been working on LS1028ARDB board and I found the switch port seems discard the udp multicast address except for 224.0.0.0 to 224.0.0.225.

Besides, I tried tcpdump -i swp0 and still can not capture any multicast udp. (here I use swp0 as a single port mode). kernel version is NXP Real-time Edge Distro 2.2, linux 5.10.72-rt

From my point of view, the udp multicast address discarded on the mac layer. But I can not find the MAC register of ls1028 which control either drop or receive all multicast udp.

Can anyone tell me which register is used for it?

If I'm wrong please tell me how to fix it in order to receive all multicast udp address?

Thanks

[h_a_i]

您好，我这用您官方的镜像和测试版，使用电脑发送udp包，swp0接收，还是无法接收到224.0.1.0以上的udp包。您帮忙看一下是什么原因。
谢谢您
好，我用你们的官方图片和测试版通过电脑发送udp数据包，swp0收到了，但是我仍然无法接收到224.0.1.0以上的udp数据包。请帮忙看看原因是什么。

谢谢

[yipingwang]

I have tested the case in RT-edge-v2.2 with kernel 5.10.72, I can capture all multicast UDP frames, not only from 224.0.0.0 to 224.0.0.225.
the log is attached.

Thanks

[xinliwang]

Hi @yipingwang 

Thank you for you reply

I just check the attached file and found that you just test the sending function of swp0. But my problem is for receiving multicast address. 

BTW, I'm using swp0 as single port mode.

Please help me with receiving function of swp0

Thanks.

[yipingwang]

I used two LS1028ardb board for test,
one swpx port is used for sending, one swp0 is used for receiving,

the attached log is for receiving function of swp0, it's working in standalone mode.

thanks

[xinliwang]

Hi @yipingwang 

I think there were some problems with your test that led you to get the right answer;

In your test the MAC address(f6:25:5d:67:6e:e3) is NOT multicast mac though your test multicast IP address is 239.3.3.1. which mean the multicast address you tested was fake!

The core problem should be that the MAC layer filters multicast MAC addresses.

So, as I change the mac address to the correct multicast MAC address, still can not receive any real multicast packet.

Thanks