we just got Shaw installed, with the new Hiltron modem, and it for some reason is completely blocking filesharing (actually, it's blocking every network service) to the wired PC that acts as my local server. I've configured the PC as the DMZ host, and I've had WMM both enabled and disabled, but nothing has changed. the configuration for the modem is very limited, and prevents me from actually doing much in the way of configuring.
I had this PC set up for file sharing on my old Shaw equipment before we moved here, and it worked flawlessly. the PC also has a local caching (squid) and adblocking (privoxy) proxy, as well as a local DNS cache (unbound), none of which are reachable from the local network. iptables rules are properly configured on the PC, so it isn't an issue with the PC