AM6442: Monitoring the internal CPSW ethernet frames and traffic

Hello Dhruvil,

Dhruvil Patel said:

what application in embedded Linux can be used on AM6442 to be able to monitor the traffic in the CPSW in the real time

Can you clarify specifically what about the traffic through the CPSW Ethernet ports do you want to monitor?

For example, what we commonly use to test Ethernet throughput real-time is to use the iperf3 Linux utility, which is already included in the SDK Linux build we provide.

-Daolin

Hi Daolin,

I am aware about iperf3 already. However I am looking for a bit more information then just the through put, I am looking for a command line wireshark or tshark is that included in the sdk?

Further, is it possible to pipe or mirror the ethernet frames from cpsw to an ethernet port from PRU?

Thanks,

Dhruvil

Hi Dhruvil, 

Dhruvil Patel said:

I am looking for a command line wireshark or tshark is that included in the sdk?

Would tcpdump also be able to accomplish what you need or do you need access to Wireshark gui on your AM6442 board? Using tcpdump, you can first capture all the Ethernet traffic in a pcap file and then open up that pcap file in a PC that does have Wireshark installed. If you need the Wireshark gui directly on AM6442, then that would not be something provided in the SDK. 

Dhruvil Patel said:

Further, is it possible to pipe or mirror the ethernet frames from cpsw to an ethernet port from PRU?

One method I can think of is to implement a switch so that traffic from one port can be directly transmitted from to the other port in the switch. However, to my knowledge implementing a switch can only be done when the ports in the switch are of the same type (both CPSW ports or both PRU_ICSSG ports). 

Please note, I will be out of office next week so responses will likely be delayed next week.

-Daolin

Hi Daolin,

We don't necessarily need the Wireshark Gui, there is a command line version of Wireshark, popularly known as tshark: Use Wireshark at the Linux command line with TShark | Opensource.com. Good to know about the tcpdump as well. For the PRU I kind off see what you are saying, thanks for the info.

Thanks,
Dhruvil

Update:

Daolin Qiu said:

However, to my knowledge implementing a switch can only be done when the ports in the switch are of the same type (both CPSW ports or both PRU_ICSSG ports). 

I want to correct my previous statement here. What I meant to say was implementing a hardware switch can only be done when the ports in the switch are of the same type. However, I believe, if you were to configure a software switch, it can be done between any two ports. 

For example, from the steps to configure CPSW switch, just skip running the "devlink" command which is used to configure the switch as a hardware switch: https://software-dl.ti.com/processor-sdk-linux/esd/AM64X/latest/exports/docs/linux/Foundational_Components/Kernel/Kernel_Drivers/Network/CPSW3g.html#multi-port-switch-mode 

One thing to note is that it appears from Kernel 6.6, implementing a software switch between a CPSW and PRU_ICSSG port may not be straightforward, because the PRU_ICSSG ethernet port is by default configured as a hardware switch: https://lore.kernel.org/netdev/20240528113734.379422-1-danishanwar@ti.com/. This means the commands used here to setup a switch would mean the PRU_ICSSG is automatically set up as a hardware switch even without the "devlink" command: https://software-dl.ti.com/processor-sdk-linux/esd/AM64X/latest/exports/docs/linux/Foundational_Components/PRU-ICSS/Linux_Drivers/PRU_ICSSG_Ethernet_Switch.html  

-Daolin