[arin-ppml] ULA-C and reverse DNS

Owen DeLong owen at delong.com
Mon Mar 22 14:00:22 EDT 2010

On Mar 22, 2010, at 9:19 AM, <michael.dillon at bt.com> wrote:

>> I think that it makes far more sense to make a liberal GUA
>> policy that allows people to get GUA if they need it
>> regardless of whether they need it for internet or not.
>> Then, if they want it from a prefix set aside as
>> "non-routable", then, that's available, but, it's a purely
>> advisory semantic, not something coded into systems or
>> routers or whatever.
> That is as bad as PA addressing. Your address range is
> tainted as unroutable, and if you want to change that,
> you have to return the addresses and get a new range
> and renumber.
Nope... It's as bad as ULA-C _IF_ you choose to get it from
the tainted block. If you choose to get it from an un-tainted
block, then you have the option whether to connect it or not.

Printer1		link local, GUA-tainted
Printer2		link local, GUA-tainted
Fileserver1	linklocal, GUA-tainted
Fileserver2	linklocal, GUA
Webserver1	linklocal, GUA-tainted
Webserver2	linklocal, GUA
Mailserver	linklocal, GUA-tainted, GUA

> ULA-C allocations are what they are, and are permanent
> allocations. You simply do not use them for traffic
> which needs to be routable on the Internet.
Permanent allocations are an absolutely horrible idea.  They
create a monotonically decreasing resource which cannot be
reclaimed when abandoned. Implementing such a thing
reflects a failure to learn from our IPv4 experience.

> Everybody has a link local adddress. Things that are only
> used inside the org, have a ULA address. FileServer2 is
> for customers to upload some data. WebServer1 handles
> the company intranet webservices, WebServer2 is the external
> Internet webserver. And the Mailserver works for everyone,
> everywhere, however they may roam.
And you've got exactly the same scenario as ULA-C.

Now, s/GUA-tainted/GUA-not-routed/g
And you have an option not afforded to ULA, but, which may
be desirable to some enterprises which is that you can make
the not-routed block routed if you desire to.

A liberal GUA policy which:

	1.	Does not assume prefixes will be routed
	2.	Offers the user a choice of "tainted prefixes" if they choose
	3.	Is coupled with a modest fee structure (much more modest
		than the current fee structure, on the order of $300 initial
		and $50 annual, for example)

Would offer pretty much all that is good about ULA-C without making
it a tool for end-running addressing policy.


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