Re: wet-behind-the-ears whippersnapper seeking advice on building a nationwide network

[Brett Frankenberger <rbf+nanog () panix com>]

On Tue, Sep 20, 2011 at 04:13:57PM -0400, Dorn Hetzel wrote:
> "full time connection to two or more providers" should be satisfied when the
> network involved has (or has contracted for and will have) two or more
> connections that are diverse from each other at ANY point in their path
> between the end network location or locations and the far end BGP peers,
> whether or not the two or more connections are exposed to one or more common
> points of failure, as long as their are any failure modes for which one
> connection can provide protection against that failure mode somewhere in the
> other connection.

The GRE tunnel configuration being discussed in this thread passes this test. 
Consider the following:
   ISP #1 has transit connections to upstream A and B.
   ISP #2 has transit connections to upstream C and D
   ISP 1 and ISP 2 peer.

Customer gets a connection to ISP #1 and runs BGP, and, over that
connection, establishes a GRE tunnel to ISP #2, and runs BGP over that
also.

I assume your last clause requires that each connection provide
protection against a failure more in the other connection (not just
that one of the two provide protection against a failure mode on the
other).  This is satisfied.  In my example:

ISP #1 provides protection against ISP #2 having a complete meltdown.

ISP #2 provides protection against ISP #1 losing both its upstream
connections.

     -- Brett