Re: [mpls] Comment on draft-ietf-mpls-tp-ethernet-addressing

["Joel M. Halpern" <[e-mail]>]

That suffices.
Thank you,
Joel

PS: My personal guess is that on a link known correctly to be 
point-to-point FF-FF-FF-FF-FF-FF would work fine.  But that is a WG 
call, and the new text is sufficient.

On 12/3/2012 9:30 AM, Stewart Bryant wrote:
> Joel
>
> I have changed the text to:
>
> Another approach which may be considered is to use the Ethernet
> broadcast address FF-FF-FF-FF-FF-FF as the destination MAC address in
> frames carrying MPLS-TP packets over a link that is known to be
> point-to-point. This may, however, lead to excessive frame distribution
> and processing at the Ethernet layer. Broadcast traffic may also be
> treated specially by some devices and this may not be desirable for
> MPLS-TP data frames.
>
> In view of the above considerations, the approach which SHOULD be used,
> is therefore to configure both nodes to use the method descibed in this
> document which uses, as a destination MAC address, an Ethernet multicast
> address reserved for MPLS-TP for use over point-to-point links. The
> address allocated for this purpose by the Internet Assigned Numbers
> Authority (IANA) is 01-00-5E-90-00-00. An MPLS-TP implementation MUST
> process Ethernet frames received over a point-to-point link with this
> destination MAC address by default.
>
> Which I think should address your concern
>
> - Stewart
>
>
>
> On 26/11/2012 16:49, Joel M. Halpern wrote:
>> Stewart,
>>     Your description is what I would have expected.
>>  However, sectio 2 of this document recommends that implementations
>> use this multicast address on pt-to-pt MLS-TP links.  There is no
>> discussion of negotiation, discovery, or even configuration.  The text
>> as written seems to simply assume that using this multicast address
>> will work. Your description clearly says that it won't work.
>>
>> Yours,
>> Joel
>>
>> On 11/26/2012 5:59 AM, Stewart Bryant wrote:
>>> On 16/06/2012 20:10, Joel M. Halpern wrote:
>>>> In reviewing this document (sorry I am a day late for the WG LC end),
>>>> a question occurred to me regarding the material in section 2.
>>>>
>>>> Is there reason to believe that existing implementations will process
>>>> received frames on pt-to-pt Ethernet links where the destination
>>>> address is 01-00-5E-90-00-00?  If so, should that reason be mentioned
>>>> (or am I just missing the obvious here?)  If not, is this a safe
>>>> recommendation?
>>>>
>>>> Otherwise, this is clear and useful.
>>>> Thank you,
>>>> Joel
>>>
>>> Hi Joel, I only just noticed that I did not reply on this.
>>>
>>> An MPLS-TP LSR  will reject all ethernet packets received on addresses
>>> that it is not configured to receive packets on. This is how Ethernet
>>> interfaces work. Thus an existing implementation will ignore packets
>>> sent with a MAC address of 01-00-5E-90-00-00, since the address is not
>>> meaningful to it and thus will not have been configured for reception.
>>>
>>> Regards
>>>
>>> Stewart
>> .
>>
>
>