Network Time Protocol (NTP) is a TCP/IP protocol used to synchronize computer clocks across data networks. NTP was developed in the 1980s by D.L. Mills at the University of Delaware to achieve highly accurate time synchronization and to sustain the effects of variable latency over packet-switched data networks through a jitter buffer.

SNTP clients should operate at the edge of the synchronisation tree and SNTP servers used as stratum 1 located next to a clock source. SNTP uses UDP port 123 for the destination however unlike NTP, any UDP port can be used for the source port thereby providing a method for distinguishing between clients. When querying ntp servers with the command ntpdate, I can use the -u argument to make the source port an unrestricted port (port 1024 and above). With ntpd, which is meant to run in the background, I can't seem to find a way to turn this option on. So the source port is always 123. It's playing around horribly with my firewall configuration. TimeTools is a UK-based manufacturer of NTP servers and precision timing equipment. Based on GPS and Multi-GNSS technology, our products provide a reliable, accurate and traceable source of time, inside your firewall. Port(s) Protocol Service Details Source; 123 : udp: NTP: Network Time Protocol (NTP) - used for time synchronization Security Concerns: It provides both information and possible avenue of attack for intruders. Info gathered can include system uptime, time since reset, time server pkt, I/O & memory statistics and ntp peer list.

When querying ntp servers with the command ntpdate, I can use the -u argument to make the source port an unrestricted port (port 1024 and above). With ntpd, which is meant to run in the background, I can't seem to find a way to turn this option on. So the source port is always 123. It's playing around horribly with my firewall configuration.

This site uses cookies for analytics, personalized content and ads. By continuing to browse this site, you agree to this use. Learn more Network Time Protocol (NTP) has two different implementations with similar basic functionality - ntp and chrony. Both ntp and chrony can operate as an NTP client in order to synchronize the system clock with NTP servers and they can operate as an NTP server for other computers in the network. Each implementation has some unique features.

Dec 02, 2016 · Google's turned on a set of public network time protocol (NTP) servers. You'll find the servers at time.google.com – which resolves to 216.239.35.0, a rather less pretty IP address than the 8.8.8.8 and 8.8.4.4 Google uses for its public domain-name system (DNS) servers. There's also time2.google.com at 216.239.35.4, time3. at .8 and time4. at

SNTP clients should operate at the edge of the synchronisation tree and SNTP servers used as stratum 1 located next to a clock source. SNTP uses UDP port 123 for the destination however unlike NTP, any UDP port can be used for the source port thereby providing a method for distinguishing between clients. When querying ntp servers with the command ntpdate, I can use the -u argument to make the source port an unrestricted port (port 1024 and above). With ntpd, which is meant to run in the background, I can't seem to find a way to turn this option on. So the source port is always 123. It's playing around horribly with my firewall configuration.