ISP customer assignments

Joe Greco jgreco at
Tue Oct 6 00:14:01 UTC 2009

> The address space is daunting in scale as you have noted, but I don't see 
> any lessons learned in address allocation between IPv6 and IPv4.

That's probably because IPv4 was a technology where the expected host
address allocation strategy was (last+1) and IPv6 is a technology where
the default host address allocation strategy involves shooting into an
extremely extra-sparse 64-bit address space.  These are incredibly 
different things.

> Consider 
> as a residential customer, I will be provided a /64, which means each 
> individual on Earth will have roughly 1 billion addresses each. 

Um, no.  Unless by "roughly" we use a definition where 1 is roughly
equal to 18 billion.  Yes, that's right, a /64 is 18 billion *billion*.

Generally speaking, we shouldn't *want* end users to be provided with a
single /64.  The number of addresses is not the point.  The idea of
getting rid of the horribleness that is CIDR is the point.

For example, consider the network  If I assign that to
an Ethernet interface, I have a problem because two addresses in the
middle of the network, and, are less-than-
fully-usable because stupid idiot retards out on the Internet will see
that last octet and will firewall it.  And by "stupid idiot retards,"
I don't necessarily mean end users, I mean *VENDORS*.  (You know who 
you are.)

The current revision of IPv6 introduces a way to nail down the boundary
between network and host.  This is fantastic, from an implementation
point of view.  It simplifies the design of silicon for forwarding
engines, etc.

And here's the kicker.  If it /really/ bothers you, just bear in mind
that having another whole 64 bits as the host space means that if ever
the V6Internet is in crisis and is running out of IP space, unlike IPv4,
we can "fix" that problem by changing the addressing strategy within
the local AS.

> Organizations will be provided /48s or smaller, but given the current 
> issues with routing /48's globally, I think you will find more 
> organizations fighting for /32s or smaller... 

Oh puhhhhhleeeze.  Where do we get these newbies from.  Part of the 
reason for forming a group such as NANOG was that there were lots of 
routing issues; we still see requests for help for that sort of stuff
today on the IPv4 Internet.  Anyone who remembers the fun days of the 
early commercial Internet would likely say that we've got it easy

> so what once was a 
> astonomical number of addresses that one cannot concieve numerically, soon 
> becomes much smaller.  I can see an IPv7 in the future, and doing it all 
> over again... I just hope I retire before it comes... The only difference 
> I can see between IPv4 and IPv6 is how much of a pain it is to type a 128 
> bit address... 

You don't do that.  Or at least, you shouldn't do that.  :-)  We have a
fairly reliable DNS system these days...

> Just like back in the day when Class B networks were 
> handed out like candy, one day we will be figuring out how to put in 
> emergency allocations on the ARIN listserv for IPv6 because of address 
> exhaustion and waste.

Not likely to happen in this century.

One of the lessons that *was* learned was that it's better to go too
big than too small.  People just have a rough time visualizing how
massively immense 2^128 actually is.  But this discussion is really
not relevant to NANOG; if you wish to fight this battle, the people
with the clue-by-fours are over on the IPv6 lists.

> Food for thought...

Only if by "food" you mean "I went down to Lardburger and ate until I
had a heart attack and died."

You're not bringing anything new to the table, least of all in the fact
department, which is about the only way you could manage to convince
people that there's a problem.

And the very thing you're complaining about would actually be the
obvious safety valve if there's a problem.  That immense, extremely
sparse space that forms the host portion of an IPv6 address...  that
is where we dip into in the extremely unlikely event there's a problem.

... JG
Joe Greco - Network Services - Milwaukee, WI -
"We call it the 'one bite at the apple' rule. Give me one chance [and] then I
won't contact you again." - Direct Marketing Ass'n position on e-mail spam(CNN)
With 24 million small businesses in the US alone, that's way too many apples.

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