The OpenFlow 1.0 reference implementation code includes several uses of
OFPP_MAX. Most of them imply that a port number must be less than
OFPP_MAX. Two comments in OF1.0 openflow.h are explicit about this:
uint16_t port; /* Port that queue belongs. Should
refer to a valid physical port
(i.e. < OFPP_MAX) or OFPP_IN_PORT. */
uint16_t port; /* Port to be queried. Should refer
to a valid physical port (i.e. < OFPP_MAX) */
One comment in OF1.3.1 openflow.h is also explicit about this:
uint32_t port; /* Port to be queried. Should refer
to a valid physical port (i.e. < OFPP_MAX),
or OFPP_ANY to request all configured
queues.*/
On Tue, Apr 30, 2013 at 06:09:41AM +0000, Zolt?n Lajos Kis wrote:
> I think ports can go from 1 to OFPP_MAX inclusive, and the mistake is
> in the comment on page 88 (should be <= OFPP_MAX).
>
> Every xxx_MAX constant in OpenFlow refers to the last usable id (OFPP_MAX,
> OFPG_MAX, OFPM_MAX, OFPTT_MAX, ...). In most cases the structs explicitly say
> so.
> Ports are only special, because there the numbering starts from 1, which
> makes the total number equal to the last usable id.
>
> Zoltan.
>
> >-----Original Message-----
> >From: openflow-discuss-boun...@lists.stanford.edu [mailto:openflow-
> >discuss-boun...@lists.stanford.edu] On Behalf Of Ben Pfaff
> >Sent: Tuesday, April 30, 2013 7:54 AM
> >To: Bertrand Bonnefoy-Claudet
> >Cc: openflow-discuss@lists.stanford.edu
> >Subject: Re: [openflow-discuss] Port numbering and OFPP_MAX
> >
> >On Mon, Apr 29, 2013 at 08:36:57PM -0500, Bertrand Bonnefoy-Claudet wrote:
> >> Here is a minor point in the OpenFlow 1.3.1 specification (and most
> >> previous versions) that I would like to clarify.
> >>
> >> Page 42 says that ports are numbered starting from 1 and that OFPP_MAX
> >> is the maximum number of "normal" ports a switch can have.
> >>
> >> Page 88, on the other hand, says that a valid physical port should
> >> have a number "< OFPP_MAX".
> >>
> >> So, to my understanding, page 42 implies OFPP_MAX is a valid port
> >> whereas page 88 implies the contrary.
> >
> >This sounds like a mistake. I imagine that it arose because the earliest
> >versions of OpenFlow numbered ports starting from 0. The intent is that port
> >numbers are greater than 0 and less than OFPP_MAX.
> >_______________________________________________
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> >openflow-discuss@lists.stanford.edu
> >https://mailman.stanford.edu/mailman/listinfo/openflow-discuss
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