After completing a Lync Server 2013 install I got some feedback that federation with Office 365/Lync Online users wasn’t working properly. On the other hand, federation with other Lync-enabled organisations was ok. Some of the symptoms, that I also verified using my own Lync Online account, were:
- On-premise users could see Lync Online users’ presence, and initiate IM
- Lync Online users could NOT see on-premise users’ presence, NOR could they initiate IM (message would time out with error message)
- Once IM was initiated from on-premise user to Online user, all modalities would work (although presence would take some time to update)
The only references I came across searching for an answer, were all related to federation problems FROM on-premise TO the Online users. Also, since I did have one-way Federation, it would appear that the External Access setup including Hosting Provider setup for Lync Online and Edge configuration to allow such federation was in place.
Troubleshooting the issue by logging the on-premise environment turned out empty, with no reference to a possible solution. Logging from the other end is not possible, so the only thing I was left with was client-side log from the user on the Lync Online account. Looking for something to point me in the right direction, I notice the following log entry:
ms-diagnostics: 1046;reason="Failed to connect to a federated peer server";
fqdn="sip.contoso.com:5061";ip-address="[2001:XXXX:XXXX:XXXX::93:216]";
peer-type="FederatedPartner";winsock-code="10060";
winsock-info="The peer did not respond to the connection attempt";source="sipfed0E.online.lync.com"
Seems like the Lync Online solution was actually trying to get the federation traffic going on IPv6. This is probably something Microsoft have prepared for in the event of a future Lync Server 2013 Online service (??), and a feature that is not shared by other Lync Server 2010 on-premise or hosted - and which is why that federation would still work. The IPv6 reference on the on-premise server was something originally designed and implemented, but later disabled in both Lync and server OS due to various problems I was facing during the install (example: registry IPv6 disable):
The end to this story was to remove all AAAA records in external DNS, since some providers will actually try and route traffic via IPv6, whenever possible.
After the IPv6 records were gone, federation with Lync Online users works from both ends.
