igb(4) txcsum6 broken in few cases

[Julian Kornberger]

Hi Sepherosa,

I attached a dump. I can provide bigger dumps, but not in public, 
because they might contain sensitive data.
The outgoing UDP packets are created by my fastd kernel module [1] that 
is a simple UDP tunneling protocol that encapsulates IP packets using 
M_PREPEND. Some code is similar to if_vxlan.c.

ICMPv4 echo requests inside of the tunnel lead to invalid checksums in > 
95% of the cases. But also other packets types are affected.

[1] https://github.com/digineo/fastd/blob/master/kmod/fastd.c

Regards,
Julian


On 26.09.2017 07:10, Sepherosa Ziehau wrote:
> It will be more than helpful, if you can provides tcpdumps.