You are the only person who has mentioned reverse DNS lookups. However, it is true that you do in fact need to already know the identity of the sending MTA/MSA before you can do a "reverse DNS lookup". What does this have to do with the price of tea in China? And what value do you think a reverse DNS lookup adds to the identity information you already (obviously) have? -- The fact that there's a Highway to Hell but only a Stairway to Heaven says a lot about anticipated traffic volume.
-----Original Message----- From: Michael Thomas [mailto:mike@fresheez.com] On Behalf Of Michael Thomas Sent: Monday, 8 July, 2019 19:12 To: Keith Medcalf; nanog@nanog.org Subject: Re: SHAKEN/STIR Robocall Summit - July 11 2019 at FCC
Jon Callas, Eric Allman, the IETF security geek contingent and even me disagree with you. rfc 4871 disagrees with you. STD 76 disagrees with you. Trillions of signed messages disagree with you. Steve Bellovin probably disagrees with you too since you seem to be under the illusion that a reverse DNS lookup tells you anything useful.
::eyeroll::
Mike
On 7/8/19 6:06 PM, Keith Medcalf wrote:
Wow!
You must not know much about networking or programming if you do not know how to ask the OS to tell you the address/port associated with the "other end" of a TCP connection. Obviously you know who is sending the message since they are in bidirectional communication with you at the time you are receiving the message, and you need to know where to send the "carry on James" prompts to get them to send more data...
Therefore you always know who submitted a message.