Max, On Sep 19, 2006, at 11:37 AM, Max Tulyev wrote:
David Conrad wrote:
Simply, PI to network topological leaves doesn't scale. I think it is not an argument for PI.
Right. It is an argument against PI.
You also can't scale PA when it ends. You only can allocate new one.
The difference, of course, is that PA (by definition) can be aggregated into a single announcement, thereby reducing the amount of information sloshing around the routing system. It is true that if an ISP runs out of PA prefixes to assign to their customers that they'll need to get another one and that additional prefix will need to be PI, but that is a single prefix that aggregates all the customers numbered out of that prefix. This is Routing Scalability 101.
It is an argument for thinking before doing. Best way is to set up period of requesting, i.e. one company can do same kind of requests for example once in two years. It makes a company think twice about scaling ("do we requesting enough space for our grow?") and about conserving
Even if you can have a crystal ball that predicts your future addressing requirements for arbitrary amounts of time into the future, this still has a 1:1 ratio of end user organization to routing prefix and every flap of that prefix has to get propagated globally. This simply doesn't scale. Rgds, -drc