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

From: Stewart Bryant <[email-masked]>
Date: Mon, 26 Nov 2012 10:59:41 +0000

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

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From: "Joel M. Halpern" <[email-masked]>
Date: Mon, 26 Nov 2012 11:49:29 -0500

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