Dear all, I'm writting to this list because I think this is a good forum for this question, as my questions relates to the amount of routing announcements that are sent to all Internet, and actually I'm a beginner on these points. But first let me introduce myself: I'm currently working for Telefonica, at Spain, giving internet access to spanish ISP's. We've got many customers here, and so the numbers of networks being announced by our AS is currently quite big, but this number is getting bigger and bigger as we are experiencing an exponential growing of the Internet market at Spain (due also to a special service called "Infovia" specially designed here to make Internet access through normal telephone lines much easier for final users). As you will likely imagine, I'm currently in charge of routing issuess at our network (which is called Ibernet). As part of this routing issues, I'm in charge of the BGP configuration, and always following CIDR rules for peerings. Up to now, we used to have, apart from the peering with our providers, BGP peering with a couple of customers; but these customers where big enough, and they were announcing several /17, /18 and /19. But now we are receiving many petitions from much smaller ISP's asking for BGP connections. These small customers are going to announce few networks (a couple of /24, or some /23). We have no problems to configure our routers with more BGP peerings, as our routers can support it, but I'm a little bit concerned about the impact of such small announcements to the whole Internet. I know there are some controversials about network announcements flapping on the Internet, and that there is something called "dampening", whose way of working I don't know, but I guess it is for avoiding flapping; and I think that people is also worried about the amount of networks that are being announced through Internet, and indeed that some providers (Sprint ?) are filtering high prefixes (maybe higher than /19, or at least they did ?). I don't know if other providers are now, or are going in the future, to establish such kind of policies, but I'm affraid that accepting BGP peerings with small provider that are to announce only /23 or /24 could create problems in the future, first for the own customer (who could have his announcements suppressed by other AS's) and second, to the whole Internet if all carriers are doing the same. So I would like to know what is the point of view from other people, with much more experience than us in these points, about accepting these small BGP peerings. Is it really a problem, or I am worrying about nothing ? Are there any specific rules (apart, of course, from the CIDR rules) that the routing administrators of carrier providers, like us, should follow all over the world in order to make the routing at Internet much easier, or everyone can do whatever he wants ? I would very much appreciate any comments on that (and sorry for the long of this e-mail :-) Best regards ----------------------------------------------------------------------------- Nombre/Name: Javier Gonzalez Vela. Empresa/Company: Telefonica Transmision de Datos // IBERNET E-mail: jgonz@ibernet.es Telefono/Phone: + 34 1 584 08 18 Fax: + 34 1 523 44 99 -----------------------------------------------------------------------------