[rbridge] All Rbridges Multicast Address

[Dino Farinacci]

> 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.

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