Re: [PATCH] vxlan: Fix error that was resulting in VXLAN MTU size being 10 bytes too large

On Tue, 13 Nov 2012 14:37:19 -0500 (EST)
David Miller [off-list ref] wrote:

From: Alexander Duyck <redacted>
Date: Fri, 09 Nov 2012 15:35:24 -0800

quoted

This change fixes an issue I found where VXLAN frames were fragmented when
they were up to the VXLAN MTU size.  I root caused the issue to the fact that
the headroom was 4 + 20 + 8 + 8.  This math doesn't appear to be correct
because we are not inserting a VLAN header, but instead a 2nd Ethernet header.
As such the math for the overhead should be 20 + 8 + 8 + 14 to account for the
extra headers that are inserted for VXLAN.

Signed-off-by: Alexander Duyck <redacted>

Applied, thanks for the detailed commit message.

Probably need smarter code there to look at header length requirement
of underlying device as well, maybe someone will be perverse and runn
vxlan over a tunnel or IPoIB.