Due to the HDD connected to a router, the HDD does not need special formatting for Mac OS X and Windows, as the router translates between HDD and client, just like when you file share between Windows and Mac OS X.
What exact router and what exact HDD do you have? Maybe that can help? Or have you already looked at the manual of the router?
Get a Synology or QNAP NAS. Make sure it can handle your drive first.
I have one of the netgear gigabit that is supposed to handle a hdd. I found a 3tb Wd drive for $119.
Can you be more specific, please?
The model number of the router should be visible on the router itself or even the packaging. The same goes for the HDD.
Anyway, I suppose the HDD has a USB interface and the router has USB port?
Have you looked at the manual of your router yet?
"How to maximise your MacRumors troubleshooting experience" created by mad jew in 2006
I just wanted to have a conversation.