Patton electronic SmartNode 4110 Series Enabling and disabling local clock offset compensation

SmartWare Software Configuration Guide26 • SNTP client configuration

Mode: Configure

Step	Command	Purpose
1	node(cfg)#sntp-client anycast-address ip-	Set the anycast-address to ip-addressa designated
	address {port port-number}	local broadcast or multicast group address to
		which a request is sent. In addition an explicit
		SNTP server port-numberin the range from 1 to
		65535 can be defined or the argument port is
		selected, which sets the value for port to 123. If
		none of the optional argument is used the value for
		port is set to 123.

Note This command is only relevant in anycast operating-mode.

Example: SNTP client anycast address

In the following example anycast requests are sent to SNTP server at IP address 132.163.4.101 using port 123 of the SNTP server.

node(cfg)#sntp-client anycast-address 132.163.4.101 port

Enabling and disabling local clock offset compensation

The Simple Network Time Protocol (SNTP) Version 4 is an adaptation of the Network Time Protocol (NTP) that is used to synchronize computer clocks in the Internet. While not necessary in a conforming SNTP client, in unicast and anycast modes it is highly recommended that the transmit timestamp in the request is set to the time of day according to the client clock in NTP timestamp format. This allows a simple calculation to deter- mine the propagation delay between the server and client and to align the local clock generally within a few tens of milliseconds relative to the server. In addition, this provides a simple method to verify that the server reply is in fact a legitimate response to the specific client request and to avoid replays.

In multicast mode, the client has no information available to calculate the propagation delay or to determine the validity of the server unless the NTP authentication scheme is used.

This procedure describes how to enable or disable the compensation for local clock offset.

Mode: Configure

Step	Command	Purpose
1	node(cfg)#[no] sntp-client local-clock-	Enables the SNTP client’s compensation for local
	offset	clock offset. Using the no command syntax dis-
		ables this feature.

Example: Enabling the SNTP client root delay compensation

node(cfg)#sntp-client root-delay-compensation

SNTP client configuration task list 288