Re: [MBONED] WGLC for <draft-ietf-mboned-ipv4-uni-based-mcast-04.txt>

[Dino Farinacci <[e-mail]>]

>> Why isn't GLOP address allocation sufficient?
>
> In the scenario we're in (which may or may not be common in national
> research and education networks) the provider (NREN) has an ASN but  
> the
> regional networks and end sites invariably do not.   So we can only  
> get
> a GLOP allocation from the NREN.   Between a few hundred universities
> and thousands of colleges connected to that NREN, a GLOP block doesn't
> go far, especially when the NREN itself may wish to 'reserve'  
> addresses
> for its own future use (quite reasonably).

But you can go get an ASN and not use it for BGP purpose but do use it  
for GLOP addressing. Then you decouple yourself from your upstream  
provider.

> In reality there's maybe 100 sites in that NREN's scope that have an
> old style Class B allocation for whom the proposal would give up to  
> 256
> global scope group addresses.
>
> But the proposal also allows the site to manage it's allocations.  It
> doesn't have to go back to the NREN to acquire more, or to perhaps  
> annually
> justify what it has been allocated and what it's actually using.

Right, so does GLOP if you just go apply for an ASN.

>>> I think the draft answers a) sufficently well for the short to  
>>> medium
>>> term (beyond which SSM will maybe get more uptake), while b) is a
>>> topic
>>> I raised at IETF69(?) and on which I think there was a new draft
>>> posted
>>> quite recently.
>>
>> So when we get past this, there should be no issues? That is, will  
>> the
>> excuses for deploying  multicast go away?
>
> Well no, but as Dave Price said address allocation issues are  
> perhaps the
> thorniest ones in writing HowTo's for our community.    My own view is
> (as an enterprise person) the enterprise one.
>
> I agree that using SSM would be preferred, but we see practical  
> issues today,
> since as firewall and host OS support issues, that make that  
> challenging
> (both for IPv4 and IPv6 SSM).

How about this as a proposal to solve all your problems:

1) Go get an ASN and use GLOP group addresses.
2) Each GLOP group address maps to a (S,G) pair where G is the GLOP  
address.
3) Put SSM translation on the last-hop routers directly connected to all
    potential receivers so when an IGMPv2 report comes to them with a  
GLOP
    address, the router does a (S,G) PIM join.

So you run SSM in your site which extends to inter-domain SSM usage.  
This code is most likely in your routers today. You can do this with  
uni-based-mcast addresses as well.

So any other issues? Can we now move forward? Can we document this in  
the HowTo guide and move on?

Dino



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