l
NTP is developed from the time protocol and the ICMP timestamp message protocol, with
special design on the aspects of accuracy and robustness.
l
NTP runs over UDP with port number as 123.
l
Any local system that runs NTP can be time synchronized by other clock sources, and also
act as a clock source to synchronize other clocks. In addition, mutual synchronization can
be done through NTP packets exchanges.
NTP is applied to the following situations where all the clocks of hosts or routers in a network
need to be consistent:
l
In the network management, an analysis of log or debugging information collected from
different routers needs time for reference.
l
The charging system requires the clocks of all devices to be consistent.
l
Completing certain functions, for example, timing restart of all the routers in a network
requires the clocks of all the routers be consistent.
l
When several systems work together on the same complicate event, they have to take the
same clock for reference to ensure correct implementation order.
l
Incremental backup between the backup server and clients requires clocks on them be
synchronized.
When all the devices on a network need to be synchronized, it is almost impossible for an
administrator to manually change the system clock by command line. This is because the work
load is heavy and clock accuracy cannot be ensured. NTP can quickly synchronize the clocks
of network devices and ensure their precision.
There are four NTP modes: broadcast mode, multicast mode, unicast server mode, and peer
mode. The MA5616 supports all these modes.
Default Configuration
provides the default configuration for NTP.
Table 3-12
Default configuration for NTP
Parameter
Default Value
NTP-service authentication
function
Disable
NTP-service authentication
key
None
The maximum allowed
number of sessions
100
Clock stratum
16
3.9.1.1 (Optional) Configuring NTP Authentication
This topic describes how to configure NTP authentication. After NTP authentication is
configured, the function can be enabled in the network that has high requirements on security
to improve the network security and prevent unauthorized users from modifying the clock.
SmartAX MA5616 Multi-service Access Module
Configuration Guide
3 Basic Configuration
Issue 04 (2011-10-30)
Huawei Proprietary and Confidential
Copyright © Huawei Technologies Co., Ltd.
70
