I’ve tried a few times to get the Macs named on the network. On a Windows machine it’s easy – name it. On the Macs? No way.
The Sharing name, even when most items are shared still has Unknown showing in the router.
Going to some DHCP setting and naming shows the same Unknown.
Rebooting the router / machine gets the same thing.
Removing a machine from the network then rebooting the router has no effect.
Searching the Apple forums shows nothing but the above.
So in the end I did it manually. Not a big deal but the Macs should have been able to broadcast their names shouldn’t they?
Anyway, bar 3 there’s a theme :)

Edit: The network is called Amanda