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Re: New draft on embedding the RP address in IPv6 multicast address

[ post by non-subscriber. with the massive amount of spam, it is easy to
miss and therefore delete mis-posts. so fix subscription addresses! ]

Funny how, with enough IP addresses to give ~ 10^30 to each particle in the universe, there may not be enough.

Wouldn't it be simpler to just say

1.) The last 64 bits of any ASM group address specifies first 64 bits of the (anycast?) address of a RP for the group

2.) RP addresses are valid for any MAC address - i.e., for any set of lower order 64 bits.

3.) RP-RP discovery is done out of band.

Regards
Marshall


Mike O'Connor wrote:
Marshall,

I wasn't sure how the four bit RPad field is used, but the thought of a
single RP limitation occurred to me as well. I don't think that even if
the RPad allows for 16 RP's per group address it is large enough. There
have already been Access Grid conferences that have had thirty sites
join, each with their own RP. It's probably not a good idea to propose a
number that's already too small:) If there were 16 RP's per PIM domain
it might be enough.

-Mike

--
Mike O'Connor, E-mail: moc@es.net
Network Engineer Energy Sciences Network (ESnet)
East coast: +1 631 344-7410 West coast: +1 510 486-7421
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)




-----Original Message-----
From: Marshall Eubanks [mailto:tme@multicasttech.com] Sent: Thursday, October 10, 2002 12:16 PM
To: Mike O'Connor
Cc: Pekka Savola; mboned@network-services.uoregon.edu;
v6ops@ops.ietf.org; Brian Haberman; nesg@es.net
Subject: Re: New draft on embedding the RP address in IPv6 multicast
address


Yes, I think so, this requires interdomain flooding, just like interdomain MSDP in IPv4.

However, you might be able to make ASM "SSM like" in that, if you find
the group address by some means out of band, you can join to the RP and either send or receive.

It is also not clear to me how this would work in, say, a teleconference. Doesn't it limit the group to only _one_ RP? What functionality does it give that either SSM or MSDP doesn't ?

Marshall

Mike O'Connor wrote:

If all source active advertisements are carried in PIM packets won't we need to flood and prune our local source PIM packets to all or our interdomain neighbors? Would this draft accommodate PIM sparse mode?

-Mike

--
Mike O'Connor, E-mail: moc@es.net
Network Engineer Energy Sciences Network (ESnet)
East coast: +1 631 344-7410 West coast: +1 510 486-7421
Ernest O. Lawrence Berkeley National Laboratory (Berkeley Lab)




-----Original Message-----
From: Pekka Savola [mailto:pekkas@netcore.fi]
Sent: Thursday, October 10, 2002 8:20 AM
To: Marshall Eubanks
Cc: mboned@network-services.uoregon.edu; v6ops@ops.ietf.org; Brian
Haberman
Subject: Re: New draft on embedding the RP address in IPv6 multicast
address


On Thu, 10 Oct 2002, Marshall Eubanks wrote:


On Thu, 10 Oct 2002 14:21:44 +0300 (EEST)
Pekka Savola <pekkas@netcore.fi> wrote:



Hello,


Dear Pekka;

 A quick question about Section 4 :

o "plen" MUST NOT be 0 (ie. not SSM)

   o "plen" MUST NOT be greater than 96

 The address of the RP can be obtained from a multicast address by
 taking the following steps:

    1. take the last 96 bits of the multicast address

    2. zero the last 128-"plen" bits, and

    3. replace the last 4 bits with the contents of "RPad".


If "plen" is = 1 (say), which seems to be allowed, then how do I zero
the last 127 bits of a 96 bit slice of a multicast address ?

I am pretty sure this is not what you mean, but this is what I read it



to say.

The first bullet makes it implicit that those 96 bits are placed at the
beginning of a 128-bit address struct (which is assumed to have been initialized to zero).

But that should be clarified so there will be no misunderstandings,
thanks.




Regards
Marshall Eubanks
Me and Brian Haberman have submitted a new draft to
internet-drafts@ietf.org. In the interim, it's available at:

http://www.netcore.fi/pekkas/ietf/draft-savola-mboned-mcast-rpaddr-0
0.txt

"Embedding the Address of RP in IPv6 Multicast Address"

Abstract
As has been noticed, there is exists a huge deployment problem


with





 global, interdomain IPv6 multicast: PIM RPs have no way of





 communicating the information about multicast sources to other
 multicast domains, as there is no MSDP, and the whole interdomain





Any





 Source Multicast model is rendered unusable; SSM avoids these





 problems.  This memo outlines a way to embed the address of the





RP in





 the multicast address, solving the interdomain multicast problem.





The





 problem is three-fold: specify an address format, adjust the





 operational procedures and configuration if necessary, and modify
 receiver-side PIM implementations.  In consequence, there would





be no





 need for interdomain MSDP.             


It's 9 pages.



Comments are welcome, either directly or to the list(s) if

appropriate.



--

Pekka Savola                 "Tell me of difficulties surmounted,

Netcore Oy                   not those you stumble over and fall"

Systems. Networks. Security.  -- Robert Jordan: A Crown of Swords





















--
                                 Regards
                                 Marshall Eubanks

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