hey @hvendelbo
which swisscom router are you using? if you have an internet box, I guess you are looking for this here:
What is the Internet-Box DMZ function?
The Internet-Box DMZ (Demilitarized Zone) function is used to forward all incoming connections from the Internet from outside the home network to a specific device.
This is mainly required if you wish to use an additional firewall in your home network and all computers are connected to this firewall. This function is only recommended for network experts.
How do I set up a DMZ?
You can change these settings in the Internet-Box web portal at Network à Settings à DMZ. Set up the function in your home network over 'Select device'. Use of the DMZ function calls for expert know-how and a specific configuration on the end devices concerned. Contact our chargeable support service for personal advice and assistance.
full help (click "DMZ function" in the menu):
https://www.swisscom.ch/en/residential/help/loesung/netzwerkeinstellungen.html?wcmmode=disabled&endless%3Fwcmmode=disabled&endless?wcmmode=disabled&endless
if this is not what you're looking for, provide some more details please.
cheers
mattematics