On Thu, 29 Oct 2009 15:22:19 -0500
"Neulinger, Nathan" [off-list ref] wrote:

I was referring to the local IP in the "ip link add ... remote x.z.z.z
local y.z.z.z" command specifying the endpoints of the tunnel. It lets
it be added to the bridge if y is even, but not if y is odd. Why should
it care what the IP of the tunnel endpoints are?

-- Nathan

It looks like a GRE driver bug. It uses IP address for dev->dev_addr
when it really should be generating a Ethernet address when using
Ethernet wrapper mode.