[ofa-general] IPoIB arps disappearing - LRO / IP forwarding

[Or Gerlitz]

Eli Cohen wrote:
> For the benefit of all - the issue was resolved by loading the mtnic module with lro=0. It should be a general guidance to disable LRO for hosts that are configured to route packets. The reason for this is that LRO aggregates IP packets related to the same TCP stream to a single IP packet comprised of a list SKBs, and by doing that, it does not recalculate the TCP checksum. Since routing is done at the IP layer, the checksum on outgoing packets is not recalculated and the
> final destination will receive packets with bas TCP checksum.
So with the recent patch to ipoib which adds LRO, should we make the 
default being LRO off? or maybe the approach brought by this patch "net: 
Disable LRO on devices that are forwarding"
http://marc.info/?l=linux-netdev&m=121389887214425&w=2 would solve the 
problem without the user intervention?

Or.