Hi, On Wed, Nov 07, 2001 at 03:48:20PM +0100, Koepp, Karsten wrote:
All I am saying is, regardless of whether we want this type of multi-homing or not, networks originating from different AS should use PI space. It does neither save a route nor address space to make pieces of a PA block multi-homed. It only binds the network to the provider assigning the PAs. That's why I was up-set.
Whether or not an announcement is PI or PA has no influence on the number of routes visible in the global table. Using a sub-block from PA space has two advantages: - more flexible in block size (what if the customer comes back later and needs twice the space?) - more robust concerning filtering / dampening (the ISPs PA space will most likely be still visible, even if the sub-network is filtered somewhere) - if the customer goes away, the network can be given back and the route will disappear -> good for conservation *and* aggregation. The only benefit of PI is "you can keep your network if you change ISPs", which is convenient for the end customer but very expensive on the global routing system. This is why people actually ask for "stop handing out PI at all" (which I am *not* advocating here, but think about it). - and due to this pros and cons, which most people agree upon, the RIPE recommendations make sense. Gert Doering -- NetMaster -- Total number of prefixes smaller than registry allocations: 73128 SpaceNet AG Mail: netmaster@Space.Net Joseph-Dollinger-Bogen 14 Tel : +49-89-32356-0 80807 Muenchen Fax : +49-89-32356-299