ntp server configuration (LAB 11.3)
There are some things I don't understand concerning ntp, if someone could clarify I would be very grateful.
First, since the same file /etc/ntp.conf is used for client AND server configuration, how does the daemon know if it's a server or a client ? Or it is always both server and client at the same time (since I guess it has to get the correct time from somewhere unless it's stratum 1) ?
In Lab 11.3 solution it's suggested to add following lines to /etc/ntp.conf:
server 0.pool.ntp.org server 1.pool.ntp.org server 2.pool.ntp.org server 3.pool.ntp.org
On my system (ubuntu server 20.04) that doesn't do anything (visible at least). I had to change server for pool as in
for the solution to work.
In the course (LFS 211) it says:
It may be desirable to declare the local machine as a time source:
fudge 127.127.1.0 stratum 10
So, I guess the server is used to start a local ntp server ?
Bottom line question, what's the difference between server and pool keywords ?
Second thing a bit confusing for me is the syntax for allowing client connections:
# Default policy prevents queries restrict default nopeer nomodify notrap noquery # Allow queries from a particular subnet restrict 123.123.x.0 mask 255.255.255.0 nopeer nomodify notrap # Allow queries from a particular host restrict 22.214.171.124 nopeer nomodify notrap noquery # Unrestrict localhost restrict 127.0.0.1
First it says default policy prevents queries and I see a logical restrict ... no something something but then
to unrestrict localhost we add restrict 127.0.0.1 and to allow queries for a particular host we add noquery... ?
Is it just me or this is a bit counter intuitive ? What's the logic behind this ?
Thanks in advance for your time !
In the course LFS211 > Advanced Networking > NTP Applications
I think the expand title /etc/ntp.confntp should be /etc/ntp.conf (?) and also the NTP link once we expand the tab is broken