Autodiscover traffic on firewall

André Borgeld 431 Reputation points
2020-11-26T13:45:40.22+00:00

Environment: Exchange 2013 On Prem

We see a lot of autodiscover traffic that wants to leave our network but the firewall is blocking this.
My question: What can be the cause that autodiscover traffic wants to go outside and gets blocked? Without anyone complaining that something doesn't work.
Can i stop this behaviour in Exchange?

Exchange Server Management
Exchange Server Management
Exchange Server: A family of Microsoft client/server messaging and collaboration software.Management: The act or process of organizing, handling, directing or controlling something.
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  1. Andy David - MVP 147.6K Reputation points MVP
    2020-11-26T15:11:11.403+00:00
    1 person found this answer helpful.
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  1. Ashok M 6,511 Reputation points
    2020-11-26T14:31:14.137+00:00

    Hi,

    Clients will send the Autodiscover requests even after the initial configuration to get the latest information, change in URL's, mailbox moves, etc. These requests will be done by Outlook, Active sync, etc.

    Can you please be more specific on firewall? Is it the perimeter firewall blocking the autodiscover requests? If so, do you have users connecting from outside the office network i.e from external.

    Perform the EXRCA tests for Autodiscover - https://testconnectivity.microsoft.com/tests/exchange

    Also, please allow the network firewall ports for Exchange 2013
    https://video2.skills-academy.com/en-us/exchange/network-ports-for-clients-and-mail-flow-in-exchange-2013-exchange-2013-help

    42880-image.png

    https://video2.skills-academy.com/en-us/previous-versions/office/developer/exchange-server-interoperability-guidance/hh352638(v=exchg.140)
    https://video2.skills-academy.com/en-us/exchange/architecture/client-access/autodiscover?view=exchserver-2016
    https://support.microsoft.com/en-ae/help/3211279/outlook-2016-implementation-of-autodiscover

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  2. André Borgeld 431 Reputation points
    2020-11-26T19:17:53.38+00:00

    @Andy David - MVP Yeah, i was thinking the same, i will investigate it. Further with the info i've got. Many things.

    @Ashok M It's going from a client in our organization to the internet and i'm beginning to think something with O365. Thanks for the info I will investigate further tomorrow.

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