Chapter 24: Ntp Proxy - Tavve zoneranger User Manual

Chapter 24: NTP Proxy

The Network Time Protocol (NTP) allows network devices and servers to synchronize their clocks with
one or more centralized time servers, across a variable-latency network. In applications where time
synchronization across devices is important, the ability to administer time across a large number of
devices from a small number of centralized time servers using NTP is a significant advantage.
A ZoneRanger, joined to a Ranger Gateway, can provide an NTP proxy service, enabling devices in
firewall-partitioned networks to synchronize their clocks with NTP servers located in other network
zones, without requiring configuration of firewall rules to allow NTP traffic. ZoneRanger's NTP proxy
service can be configured to operate in either of two modes:
1. The ZoneRanger can obtain its time from a centralized NTP server (either directly or via a
joined Ranger Gateway), and can act as a secondary time server, responding autonomously to
NTP requests from client devices, as illustrated in the following figure.
2. The ZoneRanger can act as straight NTP protocol proxy, inspecting NTP requests received from
client devices, relaying valid requests via a joined Ranger Gateway to a centralized timer
server, and relaying server responses back to the requesting clients, as illustrated in the
following figure.
ZoneRanger 5.5 User's Guide
Figure 24-1. ZoneRanger NTP Proxy -- Mode 1
Figure 24-2. ZoneRanger NTP Proxy -- Mode 2
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