[arin-ppml] What is a "host"?

[Owen DeLong]

On Sep 17, 2010, at 3:05 AM, <michael.dillon at bt.com> <michael.dillon at bt.com> wrote:

> 
>>> Each link local address present on the network segment constitutes a
>> host.
> 
>> Because there can be 30, 50, or even 1,000 unique IP addresses on an
>> interface, but, only one link local.
> 
> This is far too technically complex for something that goes into policy.
> In order to figure out how this impacts a given organization you need to
> get a technical person involved who can find out how many link local
> addresses appear on a network segment. An ordinary person has no way
> of knowing this, and could easily buy some equipment that fails this
> test and therefore puts their ARIN allocations at risk.
> 
In essence it says count the number of IPv6-active NICs. You can't have
an IPv6-active NIC without an IPv6 link-local address. Unfortunately,
the terms NIC, interface, etc. have all become so overloaded and
convoluted that there is no way to given them consistent meaning, so,
I resorted to link-local addresses as a way to describe them accurately
for purposes of policy.

How do you buy equipment that uses IPv6 and fails this test? I don't
believe that is possible since you can't have IPv6 on an interface
without a link-local address on the interface.

IP Address allocations are not handled by people so completely
non-technical that they can't count the number of interfaces that
require IPv6 addresses. If they are, then, that organization needs
to hire someone that can count NICs to handle their IP address
policy interactions.

> And this does not address the main issue which is virtualization of
> servers, networks, switches and routers. For instance, do virtual network
> segments count?
> 
Each virtual interface on the virtual network segment would have a link
local if it supported IPv6, so, yes, they would count.

> Policy needs to be straightforward and avoid these kinds of technically
> complex tests which would require ARIN to send an engineer with test
> equipment to determine whether the test passes or fails.
> 
You are reading _WAY_ too much into it beyond the intent.

If you have an interface that is speaking IPv6, it should count as one host.
If you have 20 interfaces speaking IPv6, they should count as 20 hosts.
If you have 5 interfaces in a NIC-Team speaking IPv6, they should count
	as one host.

Really, counting up the number of things that require an IPv6 link
local address is _NOT_ rocket science, nor is it technically complex.

Owen