> > 'restrict 192.168.1.10' sets a null restriction set for that address. > IOW it removes all restrictions. Thanks Steve. I had a look at the 'restrict' parameters; the line I have is restrict 130.1.1.1 mask 255.255.255.0 nomodify which I understand prevents 130.1.1.1 from modifying the NTP configuration, is that correct? Thanks Antonio