Ptp - D-Link xStack DGS-3420 Series Reference Manual

xStack® DGS-3420 Series Layer 2 Managed Stackable Gigabit Switch Web UI Reference Guide
requests from clients will be forwarded to all servers, but will only be processed by one of them. In multicast mode,
the client uses a multicast MAC address as the destination MAC to reach the server. Regardless of the mode, the
destination MAC is the shared MAC. The server uses its own MAC address (rather than the shared MAC) as the
source MAC address of the reply packet. The NLB multicast FDB entry will be mutually exclusive with the L2
multicast entry.
To view this window, click L2 Features > NLB FDB Settings, as shown below:
The fields that can be configured are described below:
Parameter
VLAN Name
VID
MAC Address
Unit
Port
Click the Clear All button to clear out all the information entered.
Click the Apply button to accept the changes made.

PTP

The Precision Time Protocol (PTP) system is able to synchronize the distributed clocks with an accuracy of less
than 1 microsecond via Ethernet networks for the very first time.
PTP is a technology that enables precise synchronization of clocks in systems. PTP is applicable to systems
communicating by local area networks supporting multicast messaging including Ethernet and UDP. PTP enables
heterogeneous systems that include clocks of various inherent precision, resolution and stability to synchronize to a
grandmaster clock.
The synchronization is divided into two processes. The Best Master Clock (BMC) algorithm determines the PTP
status (master/slave) of all local ports. The synchronization algorithm computes the clock offset between the master
and slave clock. There are two mechanisms, Delay Request-response Mechanism and Peer Delay Mechanism, for
measuring the propagation time of an event message.
The PTP system has three types of PTP devices, boundary clock, end-to-end transparent clock and peer-to-peer
transparent clock. Only boundary clock can participate in the selection of the best master clock.
Figure 4-118 NLB FDB Settings window
Description
Click the radio button and enter the VLAN name of the NLB multicast FDB entry to
be created.
Click the radio button and enter the VLAN by the VLAN ID.
Enter the MAC address of the NLB multicast FDB entry to be created.
Select the unit you wish to configure.
Choose the forwarding ports for the specified NLB multicast FDB entry.
None – The port is not the forwarding port. Click the All button to select all the
ports.
Egress - The port is the forwarding port. Click the All button to select all the ports.
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