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Forrest_H's avatar
Forrest_H
Iron Contributor
Sep 14, 2021
Solved

Are the DNS records for Skype for Business Online still required when in Teams Only?

Can someone answer if I can delete the old DNS entries?

Have been running Teams only mode since March 2020.

We have a few users with the PSTN from Microsoft as Add-On. One license is for Polycom Trio (voice only) running the Teams Client app in a Conference Room.

We use a lot of the Microsoft Conferencing Add-on as well.

I cannot determine from the MS docs if we still need the old DNS entries from running Skype for Business Online.  We never had On-Prem.

Can I delete these that MS is still listing in the Org Setup wizard of the Office Admin Portal

 

Skype for Business  
CNAMEsipsipdir.online.lync.com
CNAMElyncdiscoverwebdir.online.lync.com
SRV_sipsipdir.online.lync.com
SRV_sipfederationtlssipfed.online.lync.com
  • It does also say:

    Note
    These DNS records also apply to Teams, especially in a hybrid Teams and Skype for Business scenario, where certain federation issues could arise.

    As I say, plenty of customers don't have them and never had a problem but others have when there's no SRV record. If you also have federated partners who use Skype for Business, then you'd need those records for them to federate with you.

6 Replies

  • fowler_23's avatar
    fowler_23
    Iron Contributor
    According to MS docs: yes you do.
    https://docs.microsoft.com/en-us/microsoft-365/enterprise/external-domain-name-system-records?view=o365-worldwide#external-dns-records-required-for-skype-for-business-online

    I know a lot of orgs don't and have not had problems but I've also had issues with some tenants where trying to create resource accounts is problematic if you don't have the _sipfederationtls SRV record.

    My suggestion is that there's no harm in keeping them.
      • fowler_23's avatar
        fowler_23
        Iron Contributor
        It does also say:

        Note
        These DNS records also apply to Teams, especially in a hybrid Teams and Skype for Business scenario, where certain federation issues could arise.

        As I say, plenty of customers don't have them and never had a problem but others have when there's no SRV record. If you also have federated partners who use Skype for Business, then you'd need those records for them to federate with you.

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