Folks;
I'm setting up a new NTP server to sync time for our network. I have one Linux server that needs to point to that NTP server
My 3 questions are:

1. I added the IP address for the NTP server to the "/etc/hosts" file on the Linux server. Is that all i need to do to make the Linux server point to the NTP server?

2. After pointing the Linux server to the NTP server, do i need to reboot the Linux server or restart any daemon on the Linux server? in other words, what do i need to do to make sure the changes i made in the "/etc/hosts" took affect?

3. Is there a way to test the NTP server to make sure it interact with the Linux server & will work fine if i have a timing issue on the Linux server? I want to test it so if something happens for real i don't look like a dummy

Thanks Folks in advance

What do you mean by "point to"? The alias in /etc/hosts will let you refer to the server by the name you put in /etc/hosts instead of the IP address but this is not strictly necessary; you could simply set up your NTP client to connect by IP address, although of course it's a good habit to have a name for the server.

If you have an ntp client running continuously then it will likely need to be nudged to reread its configuration. Many daemons have a way to reinitialize without having to actually shut it down completely, often by sending a SIGUSR1, but read the documentation for whatever you are running.

You seem to be missing the step where you find out what NTP client software you are running, and read its documentation to see how you tell it which NTP server to use. That should also give some hints for your third question.

If you have ntpdate, it can be run with a diagnostic option which tells you which server it connected to and what the result was. If you are on Debian or Ubuntu, note the difference between ntpdate and ntpdate-debian

When i said point to i meant they can talk to each other (in other word i want the client on the Linux box to be able to talk to the NTP server.
That's why i was asking about how to add the NTP server to the Linux box as a trusted host.

one more question i have now:
Should i add NTP server IP address to the ntp.conf file on the Linux box?

If by "trusted" you mean you have hosts.deny or firewall rules or something, then you still need to tell us more about those.

Now that you have it in /etc/hosts and have checked that you can ping by name (you have, yes?) it's probably better to put in the host name from /etc/hosts

Sorry if my questions weren't clear.
let me clarify it a little more.
What should i do to connect a Linux server to NTP server?

If you've done all which is listed here, and it doesn't work, maybe you can elaborate on what does work. Can you ping the server? Can you run ntpdate and see that you connect to it?