[Re: http://tools.ietf.org/search/draft-hain-ipv6-ulac-01]

Sun Apr 25 22:39:58 UTC 2010

On Sun, 25 Apr 2010 12:56:41 -0700
Owen DeLong <owen at delong.com> wrote:

> 
> 
> 
> On Apr 25, 2010, at 9:11 AM, sthaug at nethelp.no wrote:
> 
> >> What ISP would put a 'lifetime' on your ipv6 prefix?  That seems insane
> >> to me... they should give you a /48 and be done with it.  Even the free
> >> tunnel brokers do that.
> >> 
> >> But then I never understood dynamic ipv4 either....
> > 
> > Dynamic IPv4 isn't too difficult to understand. There are two main
> > arguments:
> > 
> > - Dynamic addresses is a way to differentiate residential customers
> > (who pay less) from business customers (who pay more).
> > 
> Which is both specious and obnoxious.
> 

No necessarily. There is an increased cost with static addresses. When
a (typically business) customer pays for one, you are selling the
ability to have that /32 or /32 + subnet regardless of where they
connect to your infrastructure. For example, if you have multiple
redundant BRASes available, it doesn't matter which one they connect
to, they'll still get the same address. If they happen to connect to
your 3G infrastructure instead, they'll get it there too.

There are some regional aggregation opportunities with that model, but
they aren't absolute. If they move out of the region in which you've
given the original assignment, the static addess needs to follow them.
So the customer with a static IP address(es) is basically paying for
their own route table slot in your network, and the corresponding
processing cost involved in maintaining that route slot i.e.
convergence. In Australia, as the country's business centres are fairly
sparse, that means a route table entry in every router in the continent.

If, other hand, you're taking about a static address that doesn't
change every time to connect/disconnect, but would change if you move
house (assuming ADSL/cable), then that is a much more tractable problem
and a different one to true static addresses.

> Given a choice between a provider which does this and one who does not, I will always choose the one that does not. Unfortunately, there is no PON vendor in my area, so I live with com cast business (on a dynamic IP because I refuse to pay their absurd mark-up on IP addresses). Given a PON vendor in my neighborhood, I'd drop Comcast in a heartbeat.
> 
> > - Dynamic addresses makes it much easier to handle customers in "bulk".
> > You can have *one* standardized form of DNS info (forward/reverse), no
> > customer defined DNS at all. You can easily move customers to a new
> > aggregation box when the current box is reaching max capacity - just
> > remember to lower your DHCP lease time beforehand. You may not need to
> > alert customers individually as long as work is done within your well
> > defined service windows. etc etc.
> > 
> This is true. However, I'd be willing to pay some amount to cover this difference. Interestingly, Comcast is the only provider where I've been unable to get a static address on a residential plan at any price. They're also the only provider that has tried to charge more for a static on business service.
> 
> > Steinar Haug, Nethelp consulting, sthaug at nethelp.no
> 
> Owen
> 
> 