I have a Ubuntu 16.04 server with Squid 3.5.22 installed.
It is configured to intercept HTTP and HTTPS traffic (Transparent). So iptables redirects were used for ports 80 and 443.
When I connect a LAN computer to it, everything works as expected except Skype for Business. By expected I mean Internet access with some HTTP and HTTPS domains blocked/redirected to another page.
However, Skype for Business fails to connect, normal skype works just fine.
I revised: https://support.office.com/en-us/article/Create-DNS-records-at-eNomCentral-for-Office-365-a6626053-a9c8-445b-81ee-eeb6672fae77?ui=en-US&rs=en-US&ad=US#bkmk_verify And added all DNS configurations on enom.
That got rid of the DNS error I was getting to another error saying service is temporarily unavailable.
Changing my gateway from my linux box IP back to my regular router allows me to log back to Skype for Business normally.
Any suggestions to why this is happening? Any solutions?
I have searched for days and have not gotten anywhere, MS fixes did not actually work.
Note1: both router and Ubuntu's WAN interface use Google's 8.8.8.8 DNS
Note2: The guide I used to install squid and configure it had these iptables rules to make everything work: http://pastebin.com/SqpbmYQQ
Note3: I just installed Sky (a Skype for Business Linux client software) on the server, and it logged in without a problem. So I think the issue is somewhere in the iptables or the network bridge on the server.
