MANU - Thank you for your reply, I can see how that would help but my problem was much more easily solved. I simply had to reboot the network switch that the Core was connected to, even though every other network device using the same switch could access the Synology with no problems. I can only guess that the switch had locked up the IP address of the Core at some point during initial installation.
Here is some initial feedback on Core, some of which I have already informed Naim about.
1. The ripping speed of Unitiserv and Core is almost, to the second exactly the same speed, although thankfully the Core doesn't spit out the CD's like my Unitiserv does.
1a. Inserting a CD into the slot on a Core is slightly more difficult that the US, I've ripped 5,000 or so CDs on a US so far and can do it without looking.
1b. For now due to the desktop software not working and the lack of Metadata editing I'm going to continue using my US to rip and the Core as a streamer / front end only. When I rip a CD with US after a short time it automatically appears as a new CD on the Core app.
2. The sound quality of each rip (US and Core) to the naked ear are identical but the file size produced is a bit bigger on the Core. I've been informed by Naim that the Core produces better rips? Has anyone done a bit test or more in-depth comparison yet?
3. There is no power switch on the back of the Core, I wonder why?
4. There is no web-page based app software on the Core like there is on US, I do hope this comes over time.
5. The Desktop software for the US recognises automatically rips that have been done with the Core, but unfortunately if you try to right click to edit the metadata it won't allow you to do so.
6. Whatever you do don't rub the Core with your hands otherwise you'll get a strange white mark on the unit which you can only remove with the supplied cloth. Very strange!
7. The ripping monitor part of the app doesn't work properly with the tracks list being ripped changing at random, although this doesn't affect the ripping in any way that I can see.
8. For some reason rips with the Core name the album artwork coverfront.jpg and not folder.jpg as per US, which means that if you play an album with Windows media player (and perhaps other players) the artwork doesn't show.
I have much more to say but didn't want to make this post too long.