Hans Petter, before you continue to create confusion in this thread please do me and us a favor and read the relevant RFC's on BGP4. Especially read the sections about EBGP, IBGP and multi-hop EBGP and all their implications. If you have done so, either all the questions and points you raise here are answered or I'm willing to assist you in any matter. RFC1771, RFC1772, RFC1773, RFC1774 plus relevant Cisco Press Literature. Thank you -- Andre Oppermann TIX Project Manager Hans Petter Holen wrote:
I have tried to follow this discussion, and stumbeled over a fundamental question when trying to reason about this: * why are exchange points so special ?
It seems to me that shared medium exchange points historicaly have used a single subnet to interconnect. Generaly it simplifies configuration and eases operations to have a single logical interface on the physical interface connected to the shared medium.
But in order to excange traffic with other partners at the exchange one needs to establish "pont to point" BGP peerings. So there is no longer any significant configuirational advantage in having all the boxes I want to talk to on a single subnet (I still need to figure out how to talk to the others by establishing BGP peerings.)
On the operational side, at least back when I was directly involved in such, it would actualy be very convenient to have logical point to point links with all my peering partners in order to better diagnose and measure traffic flows and flaws.
If this is the case, the IP addresses for the logical point to point links across the exchange would best be implementedwith IP addresses from any of the providers, or perhaps even the IPv6 equivalent of link local addresses.
I would be interested to hear comments on this approach, because if this model makes senseto implement, it would probably make sense to document this as some kind of "best current practice" for IP v6 exchanges in order to make sure that the router vendors implements the proper tools to make this easy to configure.
Looking forward to hear others opinions on this.
-hph