M A G N U M 6 K S W I T C H E S , M N S - 6 K U S E R G U I D E
Stratum 2 devices will peer with other Stratum 2 devices to provide more stable and
robust time for all devices in the peer group. Stratum 2 devices normally act as servers for
Stratum 3 NTP requests.
Stratum 3
These devices employ exactly the same NTP functions of peering and data sampling as
Stratum 2, and can themselves act as servers for lower strata, potentially up to 16 levels.
NTP (depending on what version of NTP protocol in use) supports up to 256 strata.
This is summarized in the figure below.
Stratum 3
Stratum 2
Stratum 1
Stratum 0
F
IGURE
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Different Stratum NTP servers
Special purpose receivers are available for many time-dissemination services, including the
Global Position System (GPS) and other services operated by various national governments.
For reasons of cost and convenience, it is not possible to equip every computer with one of
these receivers. However, it is possible to equip some number of computers, routers or
switches acting as primary time servers to synchronize a much larger number of secondary
servers and clients connected by a common network.
Several Magnum 6K switches with MNS-6K-SECURE can act as Stratum 2 or
Stratum 3 servers. Make sure the SNTP client is configured to synchronize
information from other Stratum 1 or Stratum 2 servers.
www.ntp.org
provides a list of NTP servers available by continent/country. For
example, as of this writing, for North America, north-america.pool.ntp.org has
over 500 NTP servers.
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