ITunes 8.1.1, Buffalo Linkstation and Zyxel Prestige 660HW
I picked myself up a nice new unibody Macbook a couple of weeks ago and today thought I'd enable the itunes server feature on my Buffalo Linkstation Live so that I could stream my music from it instead of mounting a share as I usually do. After enabling the media server feature itunes still didn't pick up the nas as a shared library so I decided that I'd update the firmware on the Linkstation as there seemed to be some media server related fixes in the latest version. This all went fine but still no media server being picked up by itunes. I did the usual try and clean out the media server database cache to ensure no stale settings where left after the flash. Nope still nothing... After a bit of talking nicely to google it seemed I needed to enable multicasting on my router. So grand I enable that check box but still nothing. The problem did turn out to be related to multicasting but it was being caught by the packet filter on the Zyxel router. I telnetted into the router and managed to disable the rule from there as I couldn't find anything related to it in the web console. Then magically itunes auto discovers the Linkstation. Hopefully this might save someone a bit of time and a lot of hassle 
