Bug 198489

Summary: vxlan: non-ECT with TOS=0x02 logs were generated
Product: Drivers Reporter: ByungYeol Woo (wby1089)
Component: NetworkAssignee: drivers_network (drivers_network)
Status: NEW ---    
Severity: normal    
Priority: P1    
Hardware: All   
OS: Linux   
Kernel Version: 4.4.0-103, 3.10.0 Subsystem:
Regression: No Bisected commit-id:
Attachments: information of log messages, kernel version, nic driver version

Description ByungYeol Woo 2018-01-16 14:17:54 UTC 
Created attachment 273645 [details]
information of log messages, kernel version, nic driver version

I use Intel 1G and 10G ethernet card with openvswitch under vxlan overlay network. Some VM started to use ECN and I found weird logs were generated about non-ECT.

I analyzed vxlan packets, but all packets had no errors. Also, vxlan outer header's ECN was normal acording to RFC6040.

I changed ethernet card from Intel's 1G/10G NIC (ixgbe and igb driver) to Broadcom's 1G/10G (tg3 and bnx2x driver), and I found there was no non-ECT log. So I guess this problem comes from ixgbe or igb driver.

https://github.com/torvalds/linux/blob/master/drivers/net/vxlan.c#L1320
https://github.com/torvalds/linux/blob/master/include/net/inet_ecn.h#L186

I contaced to Intel support community, but they recommended to contact HP first.
https://communities.intel.com/thread/120521

And I contacted to HP, but they guess this problem comes from OS. So I post this problem to bugzilla.

Please see attached file.