On Wed, 14 Jun 2017 13:38:07 -0700, Stephen Hemminger wrote: > Does this change the default? Before your patches what was the checksum > setting for the new tunnel.
Yes, it does. See the kernel patches. I realize it's a user visible change; however, given that the real reason act_tunnel_key was introduced is offloading of openvswitch and openvswitch doesn't use it yet and I very much doubt there are other users, I'm still proposing the change. It makes things aligned between the non-lwt tunnels, tc and even the current openvswitch (which includes the csum by default as well). When someone someday starts using lwtunnels with tc for other uses, this will make it much less surprising and will prevent user errors. Not mentioning performance which is in general going to be better with the csum. Furthermore, the only use case for nocsum is a compatibility with broken VTEPs from hw vendors. This is not a setup act_tunnel_key is going to be used in: in such case, you pretty much want the VXLAN internal control plane, not an external one. We're also not breaking existing Linux setups, even if there were any. Even with udp6zerocsumrx, the non-zero csumed packets are still accepted. I was notified about the current confusing behavior by Red Hat QA when they were trying to test the tunnel_key action and couldn't make it work for IPv6. When those guys needed a help of the kernel developer and the kernel developer in question had to insert a few printks to realize what's going on, no regular user would be able to use it ;-) (Of course, that's "fixable" by documentation.) Jiri
