it sounds like the ISP in there networking structure have a weird public ip sharing...
To help me better help you,
what type of dlink router is it,
ie is it a combo form your ISP,
also how is your hfs machine and what is connected to the dlink router
ie the isp modem to the internet cloud?
is you setup hfs machine > dlink router >modem >internet cloud (which is you ISP provdier...)
or is your setup hfs machine> dlink combo modem >internet cloud ....
I will need some more infomration form you to help you with your problem. If you have a dns acount, try adding that to your router as a dynamic dns host, not hfs and see if it can communicate via proxy ping or other...(not at home, try to ping you dns account host...
If not dyndns, try no-ip.org, or other free dns servers out there. i find it strange and understand the fiber infrastructure as i have worked as an ISP before... Strange though that your dlink would show a "peer address"... instead of a gateway...
also, to help me understand as there are different country rules and setting, are you located in the United states, or over seas (don't put you address or state, just the country/continent...)