[ovs-discuss] packets not being forwarded beyond 65 hops of

Ben Pfaff blp at nicira.com
Thu Aug 14 17:38:13 UTC 2014


You can increase MAX_RESUBMIT_RECURSION in ofproto-dpif-xlate.c.

On Thu, Aug 14, 2014 at 01:22:55PM -0400, Krishna Pratap wrote:
> yes Ben, you maybe right. I saw it in log file when i enabled debugging .
> 
> *2014-08-12T10:55:26.658Z|00070|ofproto_dpif_xlate(handler_1)|ERR|resubmit
> actions recursed over 64 times*
> 
> Is there a way to work around this? how can i remove this limit to see if
> it crashes or not. are there any other way to connect switches together
> apart from patch ports and Veth pairs?
> 
> Thanks,
> KP
> 
> 
> 
> On Thu, Aug 14, 2014 at 1:01 PM, Ben Pfaff <blp at nicira.com> wrote:
> 
> > On Wed, Aug 13, 2014 at 6:57 PM, Flavio Leitner <fbl at redhat.com> wrote:
> > > If it's kernel DP, then patch ports are internal ports which during TX
> > > inserts the packet (skb) into the CPU backlog queue
> > (enqueue_to_backlog())
> > > for later processing.  Later on, the backlog queue is processed
> > > (process_backlog()) and the packet is actually received by the other
> > port.
> >
> > I missed that we're talking about patch ports.  That explains the whole
> > issue.
> >
> > Patch ports are implemented in userspace regardless of the datapath in use.
> > They do not exist as ports visible from the kernel (definitely not as
> > internal
> > ports).  Hops across patch ports are "optimized out" in userspace, but the
> > recursion is limited to 64 levels, hence the issue you're seeing.
> >
> 
> 
> 
> -- 
> Best Regards,
> Krishna Pratap Singh



More information about the discuss mailing list