I have just upgraded the firmware in my Vigor2830 router and now cannot access my Exchange webmail server, which uses https port 443, from the Internet.
The latest firmware for the Vigor2830 (version 3.6.4) has added SSL VPN feature which also uses port 443.
You will need to change the default port to a different value such as 444.
Also you may need to change the default https management port from port 443 to a different value such as 444.
These settings are in:
“Web Access Control >> General Setup”
in “System Maintenance >> Management”