You are troubleshooting a computing session in which a user can't access another computer named BillsComputer on the network. You open a command prompt and type ping BillsComputer but you get an error. Next, you look in your network documentation to get the address of BillsComputer and try the ping command using the IP address and the command works. Which part of the communication process was not working when you tried the ping BillsComputer command