At 18:04 +0100 on 06/28/2005, Tony Finch wrote about Re:
Bounce/System Notification Address Verification:
On Tue, 28 Jun 2005 Valdis(_dot_)Kletnieks(_at_)vt(_dot_)edu wrote:
The first rule of any protocol is that it has to interoperate with itself.
The fact that this design *is* prone to disastrous loops when it encounters
other CBV systems with similar design flaws shows that the concept
is flawed.
You haven't demonstrated that Verizon's implementation is flawed in this way.
There is only (as I've noted in a prior message) a flaw if when
Verizon CBV probes an ISP and that ISP CBVs back in response to the
probe, Verizon instead of accepting the CBV probe and responding with
a "Good Address" reply turns around and tries to CBV the other
Server. It is the job of Verizon (and other CBV users) to recognize
the addresses used with their CBV probes and not respond with a CBV
probe when the address is used by another CBV system. You handle CBV
probles triggered by your own in-flight CBV probes do not require
your CBV code to recognize other user's CBV probe patterns (ie: you
should just CBV respond to them).
Tony.