MSFT reverse IP failure?

Christian Kuhtz chkuhtz at
Tue Feb 27 07:40:44 UTC 2018

Hah. Thanks. :)

Yes, it's a big shop..
From: Hank Nussbacher <hank at>
Sent: Monday, February 26, 2018 11:38:10 PM
To: Christian Kuhtz; Ken Chase; nanog at
Subject: Re: MSFT reverse IP failure?

On 27/02/2018 01:25, Christian Kuhtz via NANOG wrote: should reverse to<>

Optional: Remote Connectivity Analyzer<> - Initiate connectivity tests.


TCP 80 & 443



A little difficult to say what this without knowing what actually is.   If this is an Azure deployment, ReverseFqdn needs to be populated on the Public IP address resource.  Please take a look here<>


-----Original Message-----
From: NANOG <nanog-bounces at><mailto:nanog-bounces at> On Behalf Of Ken Chase
Sent: Monday, February 26, 2018 1:31 PM
To: nanog at<mailto:nanog at>
Subject: Re: MSFT reverse IP failure?

Having a client doing a test from the MSFT exchange tools site, which is failing.

NOQUEUE: reject: RCPT from unknown[]: 450 4.7.1 Client host rejected: cannot find your reverse hostname, [];

NetRange: -
CIDR: ,,
NetName:        MSFT

A bit of an oversight?


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