On Sep 20, 2011, at 2:02 PM, Jon Lewis wrote:
On Tue, 20 Sep 2011, Chris Adams wrote:
Devil's advocate: if you have links to two carriers, but they are delivered via the same LEC on the same fiber, are you multihomed? What about if you have two LECs at your facility, but the two circuits share a common path elsewhere (outside of your knowledge)?
I'd say you are. End users frequently don't know the layout of their carrier's networks, and I certainly wouldn't expect ARIN to be interested in that level of detail.
What's next? Are you going to ask if I'd require that your router have dual power supplies from different UPS's, or that if they don't have dual power, you have a router per transit connection?
It's a shame ARIN's auditors don't hang out here (or if they do, that they don't jump in and end these sorts of "what if" circle-jerks). It's a simple enough question...have they already seen applications for IP/ASN resources where the applicant was required to be multihomed and their connectivity was one leased line and a GRE tunnel with BGP to a second provider. Was the request approved?
How many providers will even provision such a service?
I know for a fact that ARIN has received and approved such requests. I do not know whether ARIN was aware of the exact details of the underlying topology in question at the time they approved the request or not. I was a consultant filling out the applications for my clients at the time. It wasn't quite exactly what you describe, it was 2 GRE tunnels to different providers over a tail circuit from a third provider. As long as you can show transit and/or peering with two ASNs (usually through a peering contract or letter of intent from the peer/transit provider), ARIN considers you to be multihomed for policy purposes. The underlying physical or logical mechanisms by which you reach those two (or more) neighbor ASNs are not ARIN's concern. Owen