[mnorth]

I have two on the same network and can see them both no trouble - they each need a separate different IP address - so change the address - also check they are both have the same network mask (e.g. 255.255.255.0). You can change the IP manually in setup, or tell it to obtain an IP address automatically if you have a router than allocates addresses. I set mine manually. Of course needs to be in the same range as the computer also.

The Thecus set-up utility can scan for a list of Thecus devices. If you can see them with this tool, but cannot browse them then its an ip setup issue.

I use network port 1 on the Thecus units - connected to a network switch.

I use second copy to synch all files between the two units.

Works fine.