Just an FYI,
I tried to work-around the lack of DNS by adding:
213.199.128.18 login.teamviewer.com
46.163.100.220 teamviewer.com
46.163.100.220
www.teamviewer.comTo my Hosts file but it wasn't enough.
After using a packet sniffer I figure that it's trying to resolve ping3. and few masterX. subdomains, so I added 1-20 to cover them all, and now it works fine.
108.59.5.129 ping3.teamviewer.com
178.77.120.100 master.teamviewer.com
178.77.120.104 master1.teamviewer.com
178.77.120.102 master2.teamviewer.com
178.77.120.104 master3.teamviewer.com
178.77.120.100 master4.teamviewer.com
178.77.120.100 master5.teamviewer.com
178.77.120.100 master6.teamviewer.com
178.77.120.102 master7.teamviewer.com
178.77.120.100 master8.teamviewer.com
178.77.120.100 master9.teamviewer.com
178.77.120.102 master10.teamviewer.com
178.77.120.104 master11.teamviewer.com
178.77.120.100 master12.teamviewer.com
178.77.120.102 master13.teamviewer.com
178.77.120.100 master14.teamviewer.com
178.77.120.100 master15.teamviewer.com
178.77.120.102 master16.teamviewer.com
178.77.120.102 master17.teamviewer.com
178.77.120.104 master18.teamviewer.com
178.77.120.100 master19.teamviewer.com
178.77.120.102 master20.teamviewer.com