The Campus Network Programmers provide accurate and reliable time services for use by networked devices, including desktops, on the UCSB campus. It is recommended that all devices be configured to automatically and periodically synchronize their clocks to an appropriate time server. Accurate time information assists in problem diagnosis, comparison of log files, maintenance of encrypted connections, and other critical activities.
There are several protocols used to synchronize time across a network. The supported services include daytime (RFC867), time (RFC868), NTP (RFC1305), and SNTP (RFC2030). In descending order of preference, one should use NTP, SNTP, time, or daytime. Use of time or daytime service is supported, but not recommended. Time services are currently accessible from off-campus locations, though this is subject to change with little advanced notice.
All of the supported time services are accessible via the DNS names ntp1.ucsb.edu and ntp2.ucsb.edu, using IP addresses 128.111.1.5 and 128.111.1.6, respectively.
The campus time servers are stratum-2 servers synchronized against a local stratum-1 clock and several authoritative off-campus servers. The off-campus sources include the Naval Observatory and the National Institute of Standards and Technology. It is recommended that on-campus servers synchronize against the local time servers and not use off-campus sources. This recommendation is intended to minimize the impact of UCSB servers on off-campus sources, as well as to avoid incorrect time information. As a specific example, all of the NIST servers either failed or provided very inaccurate time during the Y2K rollover.
Recommended update intervals depend upon the relative accuracy of the local clock and the criticality of the services on the system. NTP clients will automatically adjust their update interval, while SNTP, daytime, and time clients generally require specific configuration. Update intervals between five minutes and one hour are common, with Windows generally using a one-week interval. General configuration information for Apple and Windows platforms is available from the NIST NIST Internet Time Service; simply substitute ntp1.ucsb.edu and/or ntp2.ucsb.edu in place of NIST servers.
Problem reports may be directed to the Campus Network Programmers at cnp@ucsb.edu.
KPS