Subject: RE: v6ops:IPv4 vs. IPv6 operational costs

From: "Dwight Jamieson" <[email-masked]>
Date: Thu, 24 Nov 2005 10:25:21 -0500

Let me refine the original question.

Let's suppose that there is an enterprise using private IPv4 addressing
with NAT/ALG/FW. This enterprise is a service consumer. It doesn't offer
any public service other than a web site describing the organization. It
currently uses a few services that it has managed to get working across
the NAT/ALG. The organization has turned on sparse IPv6 capabilities.
The strategy for initial IPv6 use is to turn on dual stack in the hosts
with intra-site IPv6/IPv4 tunneling to a dual stack exit point. 

1. The enterprise wants to use a new corporate wide service that is
deployed in many sites. The service works over the public Internet or
corporate network (VPN). The service is a centrally controlled P2P type
service. The service has been developed to work on both
IPv4/NAT/ALG(proxy) and IPv6 using global addresses. 
 - will the IPv6 solution be easier/faster/cheaper to deploy?
 - will the IPv6 solution be easier/cheaper to maintain and operate?
 - will the IPv6 service typically offer enhance features (allowing
content anywhere)?
 - will it be typical for services to be developed for both IPv6 and
IPv4/ALG or IPv6 first because it's easier or IPv6 only?
 - others?

2. One of the organization's existing corporate services is made
available to work over IPv6 with global addressing and it's time for a
software upgrade for that service. What is the case for moving this
service to dual stack or even single stack IPv6?
 - ??

From the replies to the original question, it seems that many
applications will be easier/cheaper to deploy and operate using IPv6
global addresses, but it's not clear how heavy the cost factor will be
in the decision making process.

Dwight

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On
Behalf Of Tim Chown
Sent: Thursday, November 24, 2005 4:24 AM
To: [email-masked]
Subject: Re: v6ops:IPv4 vs. IPv6 operational costs

On Wed, Nov 23, 2005 at 01:21:25PM -0800, Fred Baker wrote:
> that would surprise me. My Mac is dual stacked now, and they tell me
> that Windows Leghorn (Longhorn?) will be as well. Comes that way out  
> of the box.
> 
> The question will be whether IT departments turn it on in the
> network, not whether the hosts will use it if hey do.

The question isn't only the 'cost', it's also about the benefit.  You 
also need to define 'cost' :)

Our experience of deploying dual-stack as far as open source and vendor 
provided solutions go on an enterprise of over 1,000 hosts is that the
additional 'cost' is low.   

We didn't buy new hardware specifically for IPv6.   We used to run a
parallel IPv6 routing infrastructure on BSD, but went 'properly' dual
stacked when we reprocured our old IPv4 equipment this summer.   No
extra cost per se.   The MRs on the procurement meant the new kit 
supported IPv6 features (unicast amd multicast).   The costs lie more in

managing the additional protocol, and in ensuring support staff have 
expertise to do their job.

For most platforms, deployment Just Works.   The main gaps we have lie 
in certain vender applications (e.g. Exchange) and in commercial
firewall 
product, but from the host and router platform view, the picture is
good. We have no issues running DNS, MXs, web, etc dual-stack.

We have occassional minor operational issues, but these cause very 
little extra supprot effort.

By deploying dual-stack early, we believe our staff gain the expertise
in IPv6 at an early stage.  As an educational site, we expose our CS
graduates
to be to the technology.   That is a benefit in our context.

I would imagine the backbone NRENs that have deployed would say
likewise, provided they deployed IPv6 incrementally through new
procurements 
rather than going out and buying new line cards specifically to support
IPv6 in hardware.   

You can find example deployment reports at www.6net.org.

In terms of benefits, well, restoring global addressability is
important, and in places where IPv4+NAT was used we can run IPv6 in
parallel and use point to point conferencing and other applications that
would have 
been very hard to do between two NATed sites.   Dual stack with IPv4+NAT

alongside IPv6 will be common, I believe.

Another benefit is that, as an educational site, we see new innovation
and 
interest in networking, I believe in part because catering for NATs is
no 
longer an issue.   A couple of student developed packages have attracted

(some) commercial interest.

I think Fred sums it up well when he says that had a business case been
required for the web, it probably wouldn't have happened.

-- 
Tim/::1

---

From: Brian E Carpenter <[email-masked]>
Date: Fri, 25 Nov 2005 09:05:49 +0100

>  ... The service has been developed to work on both
> IPv4/NAT/ALG(proxy)

i.e. complicated and prone to glitches

> ... and IPv6 using global addresses. 

i.e. simple and straightforward

Once you've got over the learning curve, that difference should answer
your questions,

> IPv4/ALG or IPv6 first because it's easier or IPv6 only?

That will change over time. Today, anybody looking for real customers
has to do both.

...
> service to dual stack or even single stack IPv6?

If the service is well designed, it won't care and will decide for
itself according to what network-layer services it finds. But I wouldn't
expect any current enterprise to *drop* IPv4 service for many years;
I expect to see creeping penetration of dual stack service. In ten years,
you may notice that there's no IPv4 traffic any more, at which point
you can switch it off.

    Brian