Why is my host name wrong at the Terminal prompt when connected to a public WiFi network? For three days straight, I have connected to the public WiFi network at my local library. Each day, I have seen a different prompt in Terminal. Here are some of the prompts I've seen:

zp-pc:~ russell$
mary-pc:~ russell$
normob05:~ russell$


I have check under System Preferences -> Sharing, and my computer name is "Russell's Mac". Also, I set the DHCP Client ID to "RUSSMAC" under System Preferences -> Network -> Advanced -> TCP/IP, but I still see the random host names at the Terminal prompt.

Why is my computer name changing every day?
Type in Terminal:

scutil --get HostName


If there's no HostName available, what you see is probably coming from the DNS or DHCP server.  

Set your HostName with:

sudo scutil --set HostName 'yourHostName'


That should do it.