Re: [PATCH v2 net-next 3/5] net: vxlan: enable local checksum offload

On Fri, Jan 8, 2016 at 1:36 PM, Rick Jones [off-list ref] wrote:

On 01/08/2016 01:22 PM, Alexander Duyck wrote:

quoted

 and we don't require the remote end to validate the outer checksum.

Doesn't the UDP specification require validating a non-zero checksum on
receipt?

Yes, VXLAN RFC is broken in this regard since it allows a receiver to
ignore a non-zero checksums. In Linux we always validate non-zero
checksums.

For VXLAN, UDP checksums are not enabled for IPv4 by default, but are
enabled by default for IPv6. Checksums are required for UDP/IPv6,
however RFC6935 and RFC6936 relax this requirement a bit for tunnels,
although IMO not enough to make disabling UDP checksums for VXLAN/IPv6
the default.

Tom

rick jones