I have a router connected to my cable modem. Because I have Xfinity Home I can't put the cable modem into bridge mode. I would like to set up port forwarding on the network controlled by my router. So far I've been unsuccessful. When I set up the port using the static IP address of my desktop machine on the local router and on the cable modem using the device name of my desktop canuseeme.org reports that the port forward fails. When I log into the network on the cable modem port forwarding works just fine. I have my local network set up with smb shares on my desktop machine linked to the static IP. I don't want to use the network on the cable modem because I have a 2 story house and it doesn't come close to providing decent wireless coverage on the story where it lives, let alone downstairs. Also, I like my router. It has a wide variety of management options unavailable on the cable modem.
How can I set up port forwarding on the local router without using bridge mode on the cable modem? Obviously I don't want to kneecap Xfinity Home.