Adding a Unicast SNTP Server

Up to 16 Unicast SNTP servers can be configured.

NOTE     To specify a Unicast SNTP server by name, you must first configure DNS server(s) on the device (see DNS Settings). In order to add a Unicast SNTP server, check the box to enable SNTP Client Unicast.

To add a Unicast SNTP server:

1. Click Administration > Time Settings > SNTP Unicast.

This page contains the following information for each Unicast SNTP server:

SNTP Server—SNTP server IP address. The preferred server, or hostname, is chosen according to its stratum level.
• Poll Interval—Displays whether polling is enabled or disabled.
• Authentication Key ID—Key Identification used to communicate between the SNTP server and device.
• Stratum Level—Distance from the reference clock expressed as a numerical value. An SNTP server cannot be the primary server (stratum level 1) unless polling interval is enabled.
• Status—SNTP server status. The possible values are:
Up—SNTP server is currently operating normally.
• Down—SNTP server is currently not available.
• Unknown—SNTP server is currently being searched for by the device.
• In Process—Occurs when the SNTP server has not fully trusted its own time server (i.e. when first booting up the SNTP server).
• Last Response—Date and time of the last time a response was received from this SNTP server.
• Offset—The estimated offset of the server's clock relative to the local clock, in milliseconds. The host determines the value of this offset using the algorithm described in RFC 2030.
• Delay—The estimated round-trip delay of the server's clock relative to the local clock over the network path between them, in milliseconds. The host determines the value of this delay using the algorithm described in RFC 2030.
• Source—How SNTP server was defined, for example: manually or from DHCPv6 server.
• Interface—Interface on which packets are received.
2. To add a Unicast SNTP server, enable SNTP Client Unicast.
3. Click Add.
4. Enter the following parameters:
Server Definition—Select if the SNTP server is going to be identified by its IP address or if you are going to select a well-known SNTP server by name from the list.

NOTE     To specify a well-known SNTP server, the device must be connected to the Internet and configured with a DNS server or configured so that a DNS server is identified by using DHCP. (See DNS Settings)

• IP Version—Select the version of the IP address: Version 6 or Version 4.
• IPv6 Address Type—Select the IPv6 address type (if IPv6 is used). The options are
Link Local—The IPv6 address uniquely identifies hosts on a single network link. A link local address has a prefix of FE80, is not routable, and can be used for communication only on the local network. Only one link local address is supported. If a link local address exists on the interface, this entry replaces the address in the configuration.
• Global—The IPv6 address is a global Unicast IPV6 type that is visible and reachable from other networks.
• Link Local Interface—Select the link local interface (if IPv6 Address Type Link Local is selected) from the list.
• SNTP Server IP Address—Enter the SNTP server IP address. The format depends on which address type was selected.
• SNTP Server—Select the name of the SNTP server from a list of well-known NTP servers. If other is chosen, enter name of SNTP server in the adjacent field.
• Poll Interval—Select to enable polling of the SNTP server for system time information. All NTP servers that are registered for polling are polled, and the clock is selected from the server with the lowest stratum level (distance from the reference clock) that is reachable. The server with the lowest stratum is considered to be the primary server. The server with the next lowest stratum is a secondary server, and so forth. If the primary server is down, the device polls all servers with the polling setting enabled, and selects a new primary server with the lowest stratum.
• Authentication—Select the check box to enable authentication.
• Authentication Key ID—If authentication is enabled, select the value of the key ID. (Create the authentication keys using the SNTP Authentication page.)
5. Click Apply. The STNP server is added, and you are returned to the main page.