Unable to login to Skype for Business Online with BT Home Hub 6

This is an embarrassing post to write but I hope it will help someone out there in troubleshooting! Anyway, on with the story:

Working for Modality Systems is great, but when I joined I pointed out that the daily commute was not something I fancied:

(side note - 2 hour 11 minutes - in which universe??)

Luckily working from home is one of those things you can do with the magic of Unified Communications Intelligent Communications as work really is that thing you do and not the place you go.

And that's fine until it stops working, lets set the scene.....

Its the Thursday after patch Tuesday. The previous day (Wednesday) I was in the Modality Systems main off in St Albans. Laptop had updated and working fine, Office install is Click-to-run. My user account is sync'ed from our internal domain to Office 365 and my Skype for Business account is homed in Office 365 with our setup being hybrid.

I boot my laptop and login. Direct access does its stuff, Group Policies apply, Outlook, Teams, OneNote, and SfB all load up and I start on some emails. I need to reach out to a colleague so switch to SfB and am presented by this:

"interesting" I think, I wonder why Skype is not signing in. Its been 15 minutes so since I logged onto the laptop so its really stuck, click cancel and try again but no joy..... 

Must be an O365 outage on Skype only, Teams and Outlook are fine and I can browse the internet with no issues so I plod over to the portal to check service status....

.....okay, so something about my account then, I check the internal AD and Azure AD, nothing looks out of place. I clear out the certificates from my local store....

....delete the contents of C:\Users\tobie.fysh\AppData\Local\Microsoft\Office\16.0\Lync and reboot, still no joy!

Boot up a laptop that has not been patched (and as a separate change, runs Office MSI). Still no joy. Leave that updating to latest versions and try https://testconnectivity.microsoft.com/ and see this:

Ohhhh, so something is broken on our tenant then! I click the to “tell me more” and it takes me to:

Post on our internal Teams chat and Email some of the guys in the office (feeling like a failure at this point). No-one else in the org appears to be having issues so seems to be local to me.

While awaiting a reply go think maybe Edge related (as we are hybrid the DNS records point to our on-prem Edge server so prior to the endpointcache being updated I'm going to be hitting that). I RDPto a VM inside the network (over the magic that is Direct Access and IP4 to IP6 natting) and load Lync 2013 (its a test box) and I can login to my account!

So if I'm external to our network I can login to SfB but inside the network I'm fine?? Can't be tenant related. Maybe something about our Azure AD boxes, scratching head here.....

Suggestion comes back from colleague to try my mobile app:

wait... wait... wait...

No joy.

Okay, so looks like my account, for fun I switch to bounSky and just check that I can login using my client to another estate and bang, I'm in. I test a few (Lync Server 2010, 2013 and a SfB 2015 server) all okay.

I then try a pure cloud customer.

And can't login..... I try a second customer who is hybrid and I can't login to a O365 user. On that same customer I then try a user account that is homed on-prem and CAN login (and these tenants are all hosted in different regions to the Modality tenant).

Brain is tied in knots now. About to log a ticket with O365 support but for fun think that there might be something about my home network. I turn on the hotspot fucntion of my phone connect the laptop to it and bang, the lovely 4G network allows me to login straight away.

Have a think about my network. What's changed recently. My Router. My lovely new Home Hub 6. Thanks BT, maybe its you! I reboot the router.

No joy, I then remember that I commented while doing firewall traces last week that I appeared to have an IP6 address with my new router:

I dig out the old Home Hub 5 (it was in the returns box awaiting to go back to BT) and plumb it in...... I now have an IP4 address:

And immediately desktop Skype for Business signs in.

My phone, signs in (it was on the WIFI before, go check the screenshot!)

Obviously Mr Cropley has already tweeted a reply to me:

And directs me to the source:

So - I need to support customers who wont have enabled IP6 in their tenants so as a consequence the Home Hub 5 is back in pride of place beside the fish tank and the HH6 is being say in the corner like a naughty child

I've tweeted BT to see if they can help disable IP6 on my account:

and will update if I get a response.

Update 14th December: Here's the fix! www.tobiefysh.co.uk/2017/12/unable-to-login-to-skype-for-business.html