<html><head><title></title><style type="text/css"></style></head><body><div style="font-family: Arial; font-size: medium;" dir="ltr"><div class="defangedMessage"> <div id="me81970"> <div> </div> <div> </div> <div>On Fri, Mar 24, 2017, at 03:32, Kai 'wusel' Siering wrote:</div> <blockquote class="me81970QuoteMessage" type="cite">Sorry, but as a public ASN is to serve public inter-AS-uses, why even think about private usage of a public resource? If you use a public AS internally only, you should switch to a private AS.</blockquote> <div class="me81970QuoteMessage" type="cite"> </div> <div class="me81970QuoteMessage" type="cite">What do you call "public". There are a number of cases where inter-AS interconnection is required and still it's not visible to the outside world:</div> <div class="me81970QuoteMessage" type="cite"> - Virtual mobile operators (Full-MVNO) : you usually have to interconnect (IP-wise) with one or several "home radio networks", one or more "roaming brokers" and eventually with some other entities of the eco-system</div> <div class="me81970QuoteMessage" type="cite"> - "PPP Collect" : for operators that do not have an full national deployment, it is possible to purchase wholesale DSL links delivered "over L2TP over IP". In this case you have an e-BGP connection with the local-loop operator : you announce your LNS(-es) and RADIUS server(s) and tey announce thei LAC(s) and RADIUS proxy(es). Who we even have the same story for plain IPoE.</div> <div class="me81970QuoteMessage" type="cite"> - Some private cloud interconnections are not publically visible and do not follow the rules for "regular interconnections" (may accept private IP space and max prefix length may go up to /32 in v4)</div> <div class="me81970QuoteMessage" type="cite">Some other cases exist as well.</div> <div class="me81970QuoteMessage" type="cite"> </div> <div class="me81970QuoteMessage" type="cite">In all the above cases you have eBGP sessions that exchange prefixes that in IPv4 may go up to /32 ("PPP Collect" and "IPoE Collect" we receive and have to announce almost exclusively /32 - yes that's each v4 address individually announced).</div> <div class="me81970QuoteMessage" type="cite"> </div> <div class="me81970QuoteMessage" type="cite">Useless to say that when you have several such interconnections using private ASNs things become a mess quite quickly.</div> <div class="me81970QuoteMessage" type="cite"> </div> <blockquote class="me81970QuoteMessage" type="cite"><br /> So, you need a "new" *external* routing policy to receive a (public) ASN. If your ASN does not show up in the global routing anymore, you obviously lost the need for that '"new" *external* routing policy', no?<br /> </blockquote> </div> </div> <div> </div> <div>As explained above, all thoses cases involves routing policy "external" to the organisation using the AS using the "hidden" ASn.</div> <div> </div> <div>--</div> <div>Radu-Adrian FEURDEAN</div> </div></body></html>