lync 2010 FE pool and SfB 2015 FE pool Communication problems.

isar_ns 96 Reputation points


I'm in the middle of doing side by side migration from Lync 2010 to SfB 2015 both in the same site!

I have 2015 FE pool up and running with one user in it.
I have A record in my DNS pointing to one of my servers FE2 IP to my pool name, E.G., "SKP15.domain.local" (FE Number 2 IP).

Here is the scenario:
User2015 - is logged in to SfB 2015 and sees "User2010" as Avalible.
User2010 - is logged in to Lync 2010 and sees "User2015" as Presence unknown.
User2015 - can send only one message to "User2010" and after the first message, it won't send any more.
User2010 - cant send a message at all to "User2015".

I have used SfB debugging tool and found the next error ID - 0x80072746.
I have checked my certificates, and they are valid.
The DNS seems alright as well.

Do you guys have any other suggestions?

Lync Server
Lync Server
A family of Microsoft enterprise-grade servers that provide the backbone for real-time communications within Office. Superseded by Skype for Business.
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Skype for Business
Skype for Business
A Microsoft communications service that provides communications capabilities across presence, instant messaging, audio/video calling, and an online meeting experience that includes audio, video, and web conferencing.
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Accepted answer
  1. isar_ns 96 Reputation points

    Fixed the problem by deleting the A record of the SfB FE pool and creating a new one.

1 additional answer

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  1. JimmyYang-MSFT 34,421 Reputation points Microsoft Employee


    Does this issue persist before the migration?

    Can users chat and see presence normally in individual Lync 2010 server or Skype for Business?

    Do you have any operations before this issue occurred?

    In order to narrow down this issue, could you provide detailed error message about error code 0x 80072746?

    We recommend you use Lync Connectivity Analyzer( to check your DNS configuration and other ports on the firewall.

    Besides, please check if there is any error message in the front-end server.

    For more details about how to migrate Lync 2010 to SFB 2015, you can learn it from:

    If the response is helpful, please click "Accept Answer" and upvote it.