[rbridge] Should we optimize the common case?
Radia.Perlman at sun.com
Mon Nov 13 17:11:19 PST 2006
Not sure I've been following this, but let me conjecture what people are
suggesting, and if I'm right
about the suggestion, I think it's a good idea. Correct me if it's not
what people are saying.
So I think what they are saying is the following:
a) there are cases where an RBridge has a block of addresses (like DHCP)
that it hands out to endnodes
b) in that case, it would be nice if the RBridge can announce, in its
LSP, the whole range of addresses,
rather than reporting each individually
c) the change would be an ability to express a range in the endnode
announcement. This seems easy, but
I think it would be best done with a 2nd TLV in IS-IS. The 1st TLV would
be individual addresses.
The 2nd TLV would be pairs of addresses (low, high). Or (low,
increment), as in "starting with address X,
32 addresses" (which would take up a bit less space than two MAC addresses.
I don't think of this as a hierarchical address---I just think of it as
a range of addresses reachable from
J. R. Rivers wrote:
>Sounds like we are in agreement.
>>From: Caitlin Bestler [mailto:caitlinb at broadcom.com]
>>Sent: Saturday, November 11, 2006 7:20 PM
>>To: J. R. Rivers; Silvano Gai; Guillermo Ibáñez
>>Cc: rbridge at postel.org; Radia Perlman
>>Subject: RE: [rbridge] Should we optimize the common case?
>>J. R. Rivers wrote:
>>>Hierarchical addresses assume that a single rbridge "owns" a
>>>station. With the current concept of universal mac addresses
>>>with rbridge advertisement, a single station can be reached
>>>through multiple rbriges... allowing effective dual homing.
>>>I think that hierarchical station addresses require very careful
>>There are possible deployments of rbridges where the rbridge does
>>indeed "own" the end nodes, or perhaps it "owns" them in collaboration
>>with a partner rbridge. Prime examples would include an "rbridge"
>>implemented by a hypervisor and/or NIC to support multiple virtual
>>NICs, and a bridge connecting blades on a backplane with external
>>But even in these environments, the individual OSs may want to
>>configure their MAC addresses individually. So hierarchical addresses
>>would seem to be a possible enhancement, but there is no obvious
>>path to using them generally.
>>As an option it would probably take the form of allowing
>>announcements of ranges of MAC addresses, rather than
>>requiring the rbridge to announce each individually.
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