Wireless/Redundant Edge Services xl Module Management and Configuration Guide WS.02.xx and greater

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Configuring the ProCurve Wireless Edge Services xl Module
Enabling Secure Network Time Protocol (NTP)
NTP Modes and Communications
NTP relies on the standard client-server relationship:
■ Clients send time requests to servers.
■ Servers respond with the time.
The Wireless Edge Services xl Module can operate as both a client and a server.
To configure the module as a client, you must configure an NTP neighbor that
acts as the module’s server.
NTP defines two additional modes:
■ Peer mode—Peers operate on an equal level. Peers act as both clients
and servers to each other. They send each other control queries either to
synchronize their clocks entirely or simply to exchange information.
■ Broadcast mode—Broadcast mode is similar to client-server mode.
Rather than responding to direct time requests, however, a server broad-
casts time information.
To configure your Wireless Edge Services xl Module to act as a peer to another
NTP device, add that device as an NTP neighbor in peer mode.
If your network includes an NTP server that operates in broadcast mode, you
can enable your module to listen for these broadcasts.
NTP Hierarchy
NTP uses a hierarchical system of 16 clock stratum levels (numbered 0
through 15) to define:
■ the distance (number of “hops”) from the reference clock to the Secure
NTP server
■ the associated accuracy
Figure 2-88 illustrates the top four NTP clock stratum levels.