Join us at FabCon Atlanta from March 16 - 20, 2026, for the ultimate Fabric, Power BI, AI and SQL community-led event. Save $200 with code FABCOMM.
Register now!View all the Fabric Data Days sessions on demand. View schedule
Hi,
I'm having an issue with Fabric Notebooks.
Inside our work network I can open a notebook but it can't connect to "Collaboration Server" and it doesn't appear to be able to start a session.
Outside the work network it all works fine.
Is there a list of urls/ports that need to be open?
Thanks
Ben
Hi, @bcdobbs Thanks for posting your question in Microsoft Fabric CommunityThe collaboration session is using WebSocket, can you try to check if you have any restrictions on WebSocket configuration?
Regards
Geetha
Hi @GeethaT-MSFT ,
we are facing the same issue.Please provide us with a documentation on which URLS and Ports to allow on our proxy?
Thanks
Daniel
Check out the November 2025 Fabric update to learn about new features.
Advance your Data & AI career with 50 days of live learning, contests, hands-on challenges, study groups & certifications and more!