PROCESSOR-SDK-AM62X: How to handle the kernel collapse caused by the broadcast storm

Add a little, each network is required to be independent, so you can't use the network bridge.When I want to have a broadcast storm on the Internet, the broadcast and the broadcast will take up the bandwidth. McMcalso spends a lot of resources on multicasting and broadcast messages. Therefore, we need to limit the broadcast and multicast in the CPSW hardware. Or if there is a better way to handle it, please let us know in detail, thank you!

Hello Zhaohang Lai, 

May I ask 

1. What Linux SDK Version are you using?

zhaohang lai said:

When eth1.100，eth1.200, eth1.300, any two of the net ports is connected to the same router, the memory resources will be nervous and the system crashes, and how should I solve it?

2. When any two of the eth1.xxx ports were connected to the same router, what Ethernet traffic was passing through these ports? Was the traffic generated by the connected PC or from the AM625 side? Your latest message indicate that some sort of broadcast storm was purposely introduced and impacting the eth1.xxx interfaces?

zhaohang lai said:

Therefore, we need to limit the broadcast and multicast in the CPSW hardware. Or if there is a better way to handle it, please let us know in detail, thank you!

At the moment I can only suggest two ideas but from our side we are still looking into and haven't fully investigated. I'm mentioning them here in case you would also like to look into as well.

1. Use tc filter and tc qdisc to configure a lower ingress bit rate mentioned in the below thread. Please note doing so will drop Ethernet packets in order to drop the rate and you likely can't control specifically which packets are dropped and which are not dropped: https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1482060/am6422-how-to-limit-the-eth-port-in-driver/5761873#5761873 

This other thread mentions an alternative way how to use tc filter and tc qdisc to limit multicast or broadcast rates: https://e2e.ti.com/support/processors-group/processors/f/processors-forum/1513548/processor-sdk-am62x-how-to-implement-restrictions-on-the-multicast-and-broadcast-received-by-cpsw/5831738#5831738 

2. Write and use an eBPF program that can use XDP to reduce ingress packet rate. There might be better improvements to CPU loading using eBPF to limit ingress packet rate compared to using method 1 but this hasn't been investigated on our side much yet. We do not have an example eBPF program written yet and while we are looking into it, it may take us some time to look into.

-Daolin

Hi Daolin Qiu:

1、The SDK I used is 10.01.10.04。

2、I think that when any two eth1.xxx ports are connected to the same router，the network loop is formed.MCU continuously received a lot of arp, and the soft interruptions continue to occur, so I think MCU should be able to throw away these arp or multicast.Can the CPSW hardware be done? Or is there a better way to avoid it?