So, if 1492 don’t work for you, you might want to try 1480 instead. With a lot of tracings (Now Wireshark comes into the game) I figured out, that the MTU Size was the problem! The Default MTU Size on the Mac is 1500: ifconfig en7Īs soon as I changed it to 1492 all the problems were gone! A friend told me, that I could try 1480 if 1492 didn’t work. Url: (28) Operation timed out after 300619 milliseconds with 0 out of 0 bytes receivedĪfter switching from “ Automatically” to “ Link-localonly” in the IPv6 configuration the Skype Client connects and everything worked as before. With IPv6 the connection timed out: curl -D-6
With IPv4 everything works as expected: curl -D-4 Tools like Wireshark could do the same job. So I started to dig deeper and checked all the hosts Skype for Business tries to reach from the command line (Curl is your best friend in such cases). The Skype Logs itself pointed me to the right direction: Connection issues!
The Firewall logs didn’t show anything useful. So I switched to our Guest Wifi and did some check (because it’s always the Firewall, and the guest network is nearly open - That is an insider, sorry!) and it just worked fine.Īfter joining our regular network again, the Client stopped working, on WiFi and Ethernet. HowTo Issue with Skype for Business macOS with IPv6 Sep 19, 2018Ī while ago my, Skype for Business Client on my Mac was unable to connect while I was in the Office.
