NTP

Network Time Protocol

Provide accurate timing in the network and synchronize routers, hosts, and other network devices.

Structure

NTP timing service uses a hierarchical architecture organized into 16 stratums

• An NTP primary server, or stratum-1, is synchronized with a high precision clock
• At least 175,000 hosts running NTP in the Internet

Operation Mode

• Clients and servers can operate in the multicast or broadcast mode.
• NTP client synchronize with a server in two ways
  • Query time information from and synchronize to a remote NTP server, use rdate or ntpdate
  • Synchronize with a remote server continuously and automatically, use ntpd