Should local hostname resolution work?

Just wondering if something changed, because I seem to remember this working:
Assuming the hosts are on the same VLAN and not client isolated, should a LAN client be able to reach another LAN client via hostname without the hostname/IP being added to the local DNS table on the router?

Example:

Balance1 > Switch1 > Computer1 & Computer2

Computer1: ping Computer2 : Fails
Computer1: ping Switch1: Fails
Computer1: ping Balance1: Succeeds
Computer1: ping any of the devices by IP: Succeeds
Computer1: ping any devices by hostname after adding to local DNS on router admin: Succeeds