I am forced by my ISP into having two routers. I am connected to the outside world by a combined cable modem/router (a rebadged Linksys) and inside my network I have an Airport Extreme operating in Bridge Mode and cabled to the Linksys router which provides my Wifi.

Connected to my Airport is a USB drive and I have drive sharing enabled on the Airport. Everything works successfully and my various Macs can all share the drive without a problem.

I now want to be able to access that drive from the internet. I have ticked the box marked 'Share disks over the Internet using Bonjour', but I am guessing that I need to do some sort of port forwarding on the Linksys in order to be able to make this work. I've tried forwarding 548 but this seems to do no good.

Can anybody help?