List Info

Thread: Re: v6 subnet size for DSL & leased line customers




Re: v6 subnet size for DSL & leased line customers
country flaguser name
United States
2007-12-24 11:10:28


Scott Weeks wrote:

> 
> 
> Disclaimer:  I'm still very much an IPv6 wussie... 

> 
> ---------------------------------------------
> But even in 2000 the policy was and still is:
>  /128 for really a single device
>  /64  if you know for sure that only one single subnet
will
>       ever be allocated.
>  /48  for every other case (smart bet, should be used
per default)
> ----------------------------------------------
> 
> I work on a network with 100K+ DSL folks and 200+
leased line customers, plus some other stuff.  The leased
line customers are increasing dramatically.  I should plan
for a /64 for every DSL customer and a /48 for every leased
line customer I expect over the next 5-7 years?
> 
> scott

Same disclaimer as above. But perhaps thats a benefit,
allowing the 
landscape forest view instead of the tree one.

Seems like everything good and desirable in ipv6 was
backported to ipv4, 
including router advertisements (which nobody uses, since
DHCP [yes dhcp 
can/could be made redundant] is far far preferred, even by
SOHO vendors).

All except the 4 x bitspace.

If it hasnt been backported after all this time, its likely
either 
undoable or unusable.

Since its quite likely that a minimum 50 year lifetime for
ipv4 looks to 
be in the cards, judging by bitspace, ipv6 should be
engineered for 200 
(or 50 to the 4th which makes 125000).

One would suppose that the way to do this is to do as much
as is 
neccessary to comfortably move the world onto it AND NO
MORE. We are not 
prophets. We dont even know how many prefixes the average
router will be 
able to handle in 10 years (considering that a maxed out
pc-as-a-router 
can handle millions more than the nice expensive 7600), let
alone 50.

So the first thing we do is:

Make it as big for ISP's as ipv4 was for end users, by
assigning /32 
prefixes, minus all the special purpose carvings.

To make things simple, a 4 byte AS should come with a /32.

Brilliant. We have forward ported ipv4 scalability onto
ipv6.

For what? So that end users can have nanotech networks? It
goes without 
saying that I will want my nanotech network(s) firewalled
(and natted 
for good measure).

Autoconfiguration doesnt require 64 bits. We have autoconfig
for ipv4, 
it appears to only need 16.

As stated, we dont want people to be taking their /64's with
them as 
they change ISP's, so imbuing all this uniqueness and
matching it with 
their global id's and telephone numbers is just asking for
trouble.

Unless the whole world becomes an ISP. Presto, address
shortage unless 
massive depopulation occurs over the next couple hundred
years.

We should not pretend to be building an allocation structure
that will 
not simultaneously satisify uniqueness, portability and
scalability for 
the next hundred years or so when we clearly are not.

Whats the current state with PI in ipv6? How often will it
change?

We could have reserved 90% of the first 32 bits, use the
next 32 bits to 
assign to ISP's /64 bits, and allow the ISP's to assign an
internet 
worth of customer their own internet.

Tiered routing? Geo-location routing? All easily made
available with 
another bit or two from the first /32.

Oh and the whole protocol is still useless, since proper
connectivity 
to the ipv4 network without an ipv4 stack seems to be
somewhat non 
standard. Obviously, nobody rolling out ipv6 due to address
shortage is 
going to tolerate that, and interop strategies will be used,
standard or 
not.

Expect the interop strategy to be the one with the lowest
network 
resistance. Thats nat.

IPv6 is a textbook second system syndrome. We could have all
been on it 
already without the dozens of super-freighters attached to
the 128bit 
tugboat.

Joe



[1]

about | contact  Other archives ( Real Estate discussion Medical topics )