Firewall Ports Used by Office 365

I was recently preparing for Office 365 certification (exam 70-346), I came up with several questions about firewall ports used by O365. I explored and then I thought I should document for others 🙂

Ports Used by Office 365

Following are the ports used for various purposes by Office 365.

TCP 443 - ADFS, Microsoft Online Portal (Website), Outlook 2010, Outlook 2007, Outlook Web Access (Website), SharePoint Online (Website), Lync 2010 client

TCP 25 - Mail routing

TCP 587 - SMTP relay

TCP 143/993 - IMAP migration tool

TCP 995 - POP3

TCP 80 and 443 - Online services directory, simple exchange migration tool, simple IMAP migration

STUN/UDP 3478 - Lync Online (outbound audio and video session)

RTC/UDP 50000 - 59999 - Lync Online (outbound audio and video session)

TCP 50040 - 50059 - App sharing and file transfer

STUN/TCP 443 - Lync Online (outbound audio, video, and app sharing session)

TCP 443 - Lync (Data sharing sessions)

TCP 5223 - Lync Mobile Push iOS only

References

• https://blogs.technet.microsoft.com/educloud/2011/11/30/what-firewall-ports-do-i-need-open-to-connect-to-office-365-for-education/
• https://adam-hand.com/cloud-technologies/firewall-ports-for-office-365/