Configuring Time Synchronization on AOS-S Switches

Time synchronization in a switch ensures maintaining a uniform time among all interoperating devices. Aruba Central offers the following time synchronization protocols for switches:

To configure time synchronization in a switch, complete the following steps:

  1. In the Aruba Central app, select one of the following options:
    • To select a switch group in the filter:
      1. Set the filter to a group containing at least one switch.

        The dashboard context for the group is displayed.

      2. Under Manage, click Devices > Switches.
      3. Click the AOS-S or Config icon to view the switch configuration dashboard.
    • To select a switch in the filter:
      1. Set the filter to Global or a group containing at least one switch.
      2. Under Manage, click Devices > Switches.

        A list of switches is displayed in the List view.

      3. Click a switch under Device Name.

        The dashboard context for the switch is displayed.

      4. Under Manage, click Device.

        The tabs to configure the switch is displayed.

  2. Click System > Time. The Time page is displayed.
  3. Configure the following parameters.

    Table 1: Configuring Time Synchronization Parameters

    Name

    Description

    Value

    Time Sync Method

    The synchronization method or protocol to use for synchronizing the time on the switch.

    SNTP and NTP

    Default: NTP

    Mode

    The operating mode for connecting to a time server. The following modes are supported:

    Broadcast—The switch acquires time updates from the data that any time server broadcasts to the network. The switch uses the time data from the first server detected and ignores others. If the poll interval expires thrice without the switch acquiring a time update from the first server detected, the switch accepts a time update from the next server broadcast.

    Note: To use the Broadcast mode, the switch and the time server must be in the same subnet Subnet is the logical division of an IP network.. Also, the time server must be configured to broadcast time updates to the network broadcast address.

    Unicast—The switch acquires time updates from a specific server for time synchronization. This mode requires at least one server address to be configured in the Server Address field.

    DHCP—The switch attempts to acquire a time server IP address from the DHCP Dynamic Host Configuration Protocol. A network protocol that enables a server to automatically assign an IP address to an IP-enabled device from a defined range of numbers configured for a given network.  server. If the switch receives a server address, it polls the server for time updates according to the poll interval. If the switch does not receive a time server IP address, it cannot perform time synchronization updates. This mode is applicable only for SNTP.

    Disabled—Time synchronization is disabled. You cannot disable synchronization if NTP is selected.

    SNTP

    Supported modes: Broadcast, Unicast, DHCP, and Disabled

    Default mode: DHCP

    NTP

    Supported modes: Broadcast, Unicast

    Default mode: Broadcast

     

    Default: DHCP

    Server Address

    IP address of the time server that the switch accesses for obtaining time synchronization updates. This field is applicable only when you select the Unicast mode for synchronization.

    You can configure a maximum of three time server IP addresses. When you add more than one IP address, the priority that the switch considers in selecting the IP address is the order in which you add the IP address. Therefore, the first IP address that you add will be priority 1, second IP address will be priority 2, and so on. There is no priority assigned when NTP mode is selected.

    You can delete the IP addresses by clicking the delete icon corresponding to the address. For STP Spanning Tree Protocol. STP is a network protocol that builds a logical loop-free topology for Ethernet networks., when more than one IP addresses are added, you must first delete the IP address you added last. In the case of NTP, you can delete the IP addresses in any order.

    IPv4 address

    Timezone

    The time zone corresponding to the location of the switch.

    Time zone selected from the drop-down.

    Daylight Time Rule

    The rule that the switch uses to adjust the time for Daylight Saving Time (DST Daylight Saving Time. DST is also known as summer time that refers to the practice of advancing clocks, so that evenings have more daylight and mornings have less. Typically clocks are adjusted forward one hour near the start of spring and are adjusted backward in autumn. ).

    For information about the predefined and user-defined times, see Predefined DST Rules.

    When you select the User-defined option, you must configure the beginning and ending months and dates for DST changes in the Begin Month and Day and End Month and Day fields. All DST rules begin and end at 2 a.m. on the configured dates.

    Alaska, Canada and Continental US, Middle Europe and Portugal, Southern Hemisphere, Western Europe, and User-defined.

    Begin Month and Day

    The beginning month and date for the user-defined DST changes. This field appears only when you select User-defined in the Daylight Time Rule field.

    Month and date selected from the drop-down.

    End Month and Day

    The ending month and date for the user-defined DST changes. This field appears only when you select User-defined in the Daylight Time Rule field.

    Month and date selected from the drop-down.

  4. Click Save Settings.

Predefined DST Rules

Following are the details of the beginning and ending days for the predefined DST rules:

Predefined DST Rule Name

Description

Alaska

Begin DST at 2 a.m. on March 8.

End DST at 2 a.m. on November 1.

Canada and Continental US

Middle Europe and Portugal

Begin DST at 2 a.m. on March 25.

End DST at 2 a.m. on September 24.

Southern Hemisphere

Begin DST at 2 a.m. on October 25.

End DST at 2 a.m. on March 1.

Western Europe

Begin DST at 2 a.m. on March 25.

End DST at 2 a.m. on October 25.