On Fri, Oct 28, 2022 at 09:04:52AM +0000, Neal Liu wrote: > > > Thanks for your feedback. > > > I tried to reproduce it on my side, and it cannot be reproduce it. > > > Here are my test sequences: > > > 1. emulate one of the vhub port to usb ethernet through Linux gadget > > > (ncm) > > > > We are using rndis instead of ncm. > > > > > 2. connect BMC vhub to Host > > > 3. BMC & Host can ping each other (both usb eth dev default mtu is > > > 1500) 4. Set BMC mtu to 1000 (Host OS cannot set usb eth dev mtu to > > > 2000, it's maxmtu is 1500) > > > > Not sure if it's related, but in my case (USB rndis, Debian 10 OS) it should be > > able to set MTU to 2000. > > Using rndis is able to set MTU to 2000, and the issue can be reproduced. Please NEVER use rndis anymore. I need to go just delete that driver from the tree. It is insecure-by-design and will cause any system that runs it to be instantly compromised and it can not be fixed. Never trust it. Even for data throughput tests, I wouldn't trust it as it does odd things with packet sizes as you show here. thanks, greg k-h
