[ovs-dev] [PATCH] tunneling: Force selection of an IP ID with GRE.

[Jesse Gross]

On Thu, Jun 30, 2011 at 1:29 PM, Ben Pfaff <blp at nicira.com> wrote:
> On Thu, Jun 30, 2011 at 01:09:46PM -0700, Jesse Gross wrote:
>> By default we set the DF bit on tunneled packets because we want to
>> get path MTU discovery from the underlying network.  In turn this
>> causes Linux to leave the IP ID as 0 because it believes that
>> fragmentation can never occur.  However, with GRE fragmentation is
>> still possible because we may get a large packet to be encapsulated
>> and let the local IP stack do fragmentation.  As long as packets are
>> kept in order fragments are not misassociated and everything works fine.
>> However, if there is reordering in the underlying network then packets
>> can become corrupted.  This forces selection of an IP ID for GRE packets
>> to avoid misassociation.
>>
>> Bug #6128
>>
>> Signed-off-by: Jesse Gross <jesse at nicira.com>
>
> Acked-by: Ben Pfaff <blp at nicira.com>

Pushed, thanks.