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Network Time Service

The Network Group provides three NTP (Network Time Protocol) servers for campus-connected machines. NTP servers allow workstations to determine the correct date and time with a high degree of accuracy. This is often necessary for precision control of file systems, including the distributed Andrew File System (AFS). We will also respond to UDP time requests sent by client machines.

Stratum Two Service

We provide stratum-two servers for queries. Each stratum represents one more level of direction from a highly accurate (atomic or GPS) clock which communicates with a computer directly connected to a high accuracy clock. Our stratum-two servers communicate with an on-campus GPS clock as well as several off-campus stratum-one servers.

Our Servers

We recommend client computers contact one of our stratum-two or stratum-three servers rather than directly contacting a stratum-one server. This reduces the load on such servers. Our servers are open for off-campus queries as well.

 Server Hostname
Stratum
 ac-ntp0.net.cmu.edu Two
 ac-ntp1.net.cmu.edu Two
 ac-ntp2.net.cmu.edu Two