On Sun, 25 Apr 2010 12:56:41 -0700 Owen DeLong <owen@delong.com> wrote:
On Apr 25, 2010, at 9:11 AM, sthaug@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@nethelp.no
Owen