[arin-ppml] GUA vs ULA vs ?

Steve Bertrand steve at ibctech.ca
Mon Mar 29 22:58:01 EDT 2010

On 2010.03.29 22:18, David Farmer wrote:
> Steve Bertrand wrote:
>> I am overwhelmed with the number of posts regarding the whole
>> 'Non-connected networks', so I'll admit freely that I haven't been able
>> to keep up.
> I don't see anything here that would lead me to believe that you missed
> anything critical in the conversation so far.


>> - I am in favour of eliminating NAT from IPv6
>> - I do have experience in dealing with both the ISP environment, and the
>> small-medium enterprise (across multiple boundaries), so I do see the
>> 'value' of NAT (I use the term 'value' loosely)
>> - Since I have dealt with both sides, I am willing and able to drop all
>> bias toward NAT for the purpose of this discussion
>> - I want what is best for everyone
>> Understanding:
>> - I'm a bit behind the curve on some of the abbreviations, but I believe
>> that this is correct:
>> --- ULA == Unique Local Address
>> --- GUA == Global Unique Address
>> If that is the case, here is how I feel...
> That is how I have been using them and I believe others are using them
> to mean that too.

Again, good.

Disclaimer: Although I try my best to implement the technologies and the
BCPs of the large providers, my current experience is enveloped within
the scope of having < 10k resi and a few hundred business-class clients
(BGP multi-homed). My experience with enterprise is < 5k nodes across <
50 sites.

>> We'll assume that I want to try to exploit a weakness in the policy to
>> garner space that I'll "say" won't be routed, but thinking that I'll
>> route it eventually anyways.
>> If the community decides that ARIN, not IANA, should provide 'private'
>> space, it should:
>> - be from a large block designated as such.
> Personally, I'd like to have the IETF define FC00::/8 for this purpose,
> and delegate it to IANA to allocate to the RIRs for assignment to
> organizations using process similar to those used for GUA today and
> using policies designated by the RIRs.  Among other things, this
> provides a single prefix for all the RIR's to use, and only one filter
> entry to block it globally and ULA-L (FC00::/7), also keeps ARIN from
> having to define routing policy, it comes from the IETF. I think this is
> compatible with what you are saying.

Then why is this not happening? fc00::/8 works for me, especially if it
is supported/RFC'd at the IETF level. imho, it is not in our (the
community) best interest to manage 'private' space.

>> --- why?
>> - So that the maintainers of BOGON lists (eg: Team Cymru) can hold one
>> slot in their filters for all entrants, ensuring that enough staggered
>> and unpredictable routing breakage will occur to ensure that serious
>> network engineers/architects will realize that the `cheap way out' won't
>> work
> Agreed.  And, FC00::/7 is already in their BOGON list.

Damn skippy:

#sh ipv6 route fc00::1
IPv6 Routing Table - 17929 entries
B   8000::/1 [200/0]
     via 2001:DB8:0:DEAD:BEEF::1

>> - as has been said, ARIN is not a routing policy maker. However, if
>> someone has a block allocated by ARIN that is 'supposed' to be private
>> (ie. not globally routable) but it happens to show up in the DFZ, then
>> it costs me. Perhaps it costs me for the extra tax hit I pay on my
>> filter list, or if I choose to not be diligent, a slot in my routing
>> table
>> Although I want the barrier-to-entry for IPv6 to be very low, I don't
>> like the idea of ARIN supplying ULA, unless it sits equal in cost to
>> GUA, and unless ARIN can supply it in a way that facilitates a very
>> simple method for third parties to (help) ensure that the ULA will never
>> appear in the DFZ.
> I believe GUA-PI and ULA-C should be equal cost and provided under
> either identical or essentially identical policies.  At least I think
> that is what ARIN's policies should be, it would be good if the other
> RIRs followed suite, but that is their call.
>> Otherwise, the way I see it, is that the cost of my /32 has the same
>> administrative costs to ARIN as someone else's ULA. If ARIN doesn't
>> achieve a lower administrative overhead to managing the different IP
>> space, then the price should be equal.
> Your /32 presumably is a GUA-PA provider allocation not an GUA-PI
> end-user assignment.  

You presumption is correct.

> I believe that the comparison should be between
> GUA-PI and ULA-C, not between GUA-PA and ULA-C.  

Fair enough.

> Presumably, a providers
> will be making assignments to its customers, which does involve so
> additional interaction and cost for ARIN.  Which I believe is at least
> part of the justification for the different billing models between
> providers and end-users, but that is a whole different discussion and
> not really a policy matter.

Agreed. I understand that financial matters are not relevant in policy
discussion, although it seems that throughout certain policy discussions
that it has carried weight. The 'fee', although irrelevant to legitimate
IP holders, can be the one thing that protects the Internet from the
free-loaders. Let the routing-slot holders decide.

>> Perhaps IANA should be approached for a 1918 v6. Perhaps I'm out of my
>> league ;)
> Essentially, ULA RFC 4193 is the IPv6 replacement for RFC 1918, it
> provides for random local assignment within the prefix FD00::/8, it
> provides significant statistical uniqueness, but not a guarantee of
> uniqueness.

Ahhh. I see.

> ULA-C (Central) is an expansion of this intended to
> guaranteed uniqueness through a centrally registry with assignments made
> within the prefix FC00::/8, and reverse DNS delegation should be
> available if wanted.

Thanks David for your clarification. Although I'm as confused as ever
regarding who wants what and why, you've helped me visualize a baseline
of what is actually available, which will allow me to get a better
understanding within the current discussions.



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