Subject: [rbridge] All Rbridges Multicast Address

From: Donald.Eastlake at motorola.com (Eastlake III Donald-LDE008)
Date: Thu, 17 May 2007 10:53:12 -0400

I have been looking further into getting a multicast address for TRILL.
It appears that IANA/IETF owns OUI 0x00005E and thus has 2**24 multicast
and 2*24 unicast addresses for allocation.

All the multicast addresses from 0x01005E000000 to 0x01005E7FFFFF (1/2
of them) have been allocated for IP address derived multicast addresses
[RFC1112]. There is also a draft currently in the MPLS working group
[draft-ietf-mpls-multicast-encaps-04.txt] which requests the allocation
of all multicast addresses from 0x01005E800000 to 0x01005E8FFFFF, or
1/16th of all multicast addresses, for use in connection with MPLS.

This still leaves a huge number of multicast addresses (all of
0x01005E900000 to 0x01005EFFFFFF) available for allocation by IANA.

Since we are an IETF Working group, it seems to me that we should apply
to IANA rather than to the IEEE for the All-Rbridges multicast address.
In fact, they are so plentiful that, as was discussed in the working
group earlier
(http://www3.ietf.org/proceedings/06jul/slides/trill-4/sld1.htm), I
can't see much reason not to apply for the next available block of 16
addresses, probably 0x01005E900000 through 0x01005E90000F, where ...0
would be the All-Rbridges multicast and the remaining 15 would be
reserved for future Rbridge use.

Is there any objection to this?

Thanks,
Donald

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From: dino at cisco.com (Dino Farinacci)
Date: Thu, 17 May 2007 11:28:31 -0700

> reserved for future Rbridge use.

FYI, 0x00005e is the OUI used for *IPv4* multicast addresses (ala  
0x01005e). The IETF also has 0x233300 for IPv6 multicast addresses  
(ala 0x333300).

It is of my opinion that any TRILL protocols that run right over an  
ethertype should not use the above OUI-based multicast addresses.  
That is, get an OUI from IEEE. Because right now IS-IS uses OUI  
0x0180c2 which is not IETF assigned.

And what's even more important, there may be assumptions in many  
implementations that if a MAC begins with 0x01005c, the enclosing  
packet is an IP packet. What comes to mind is IGMP-snooping switches.  
So let's just avoid this conflict or it will cause a lot of pain for  
vendors and users of such equipment.

Dino

---

From: tme at multicasttech.com (Marshall Eubanks)
Date: Thu, 17 May 2007 15:28:00 -0400

> 0x01005e). The IETF also has 0x233300 for IPv6 multicast addresses

For 0x00005e 1/2 of the addresses (where the next bit is a "zero")  
were assigned
by Jon Postal to multicast, and the others (where the next bit is a  
"one") were
used for another project. I believe that this "other project" is long  
irrelevant, but
I have no idea who would release it, whether it is still being used,  
or whether NIC
cards etc. would reject it. If this was going to go forward, this  
would have to be done.

> implementations that if a MAC begins with 0x01005c, the enclosing

e not c

> vendors and users of such equipment.

I would agree. You could be setting yourself up for years of pain and  
frustration (people
will not go out and replace / upgrade thousands of IGMP-snooping  
switches just because you asked
them too).

> Dino

Regards
Marshall

> _______________________________________________
> rbridge mailing list
> rbridge at postel.org
> http://mailman.postel.org/mailman/listinfo/rbridge

---

From: jrrivers at nuovasystems.com (J. R. Rivers)
Date: Thu, 17 May 2007 13:15:04 -0700

I second that opinion.

JR

> -----Original Message-----
> From: rbridge-bounces at postel.org 
> [mailto:rbridge-bounces at postel.org] On Behalf Of Dino Farinacci
> Sent: Thursday, May 17, 2007 11:29 AM
> To: Eastlake III Donald-LDE008
> Cc: Rbridge at postel.org
> Subject: Re: [rbridge] All Rbridges Multicast Address
>