Users Guide

NOTE:
○ Dell EMC recommends enabling PTP on the VLT port-channel member interfaces and not on the VLT port-channel
interface.
○ Tagged PTP messages using the ptp vlan command are not supported on VLT port-channel member interfaces.
○ The unicast transport method is not supported on the VLT port-channel member interfaces.
● System time settings:
When you enable PTP as the system time source, PTP sets the system time. When you enable PTP on a system, the system
cannot act as an NTP client, but can act as an NTP server.
The following table describes the system clock behavior depending on whether you choose PTP or NTP as the system time
source:
Table 9. System clock behavior
System time settings/time source System clock behavior
When PTP is the system time source:
○ You cannot configure the system as an NTP client.
○ If you configure the PTP clock and it is phase locked,
PTP sets the time.
○ If you do not configure the PTP clock and it is not phase
locked, the free-running system clock sets the time.
When NTP is the system time source: NTP client sets the system time. Even if the PTP clock runs
on the system, PTP does not set the system time.
When you configure NTP as a server: NTP provides the system clock. PTP or NTP can set the
system clock.
● You can configure PTP on the port-channel interface and the port-channel member interfaces.
○ Port-channel interface: If the link aggregation is between two peer nodes, configure PTP on the port-channel interface.
The forward and reverse paths must be symmetrical for PTP. In this case, the links of the port channel need not be the
same for both forward and reverse paths.
NOTE: Dell EMC recommends that you configure PTP on port-channel member interfaces.
○ Port-channel member interfaces: If the link aggregation spans across multiple nodes, configure PTP on the port-channel
member interfaces. PTP requires symmetrical forward and reverse paths. Therefore, configure PTP on the respective
port-channel member interfaces.
● If you have configured PTP on an interface and use the interface breakout command, it removes the PTP
configuration.
On boundary clocks, the interface breakout command removes the PTP port and changes the clock hierarchy.
Precision Time Protocol Limitations
10.5.1 does not support the following features:
● Multiple PTP timing domains
● Non-default VRF
● OS10 does not send PTP messages in the two-step mode. However, OS10 does support PTP port nodes that use the two-
step mode.
Configure Precision Time Protocol
You can configure global and interface-level settings to set up the OS10 switch to function as a PTP device. Some of these
configurations have default values assigned. For a minimum configuration to set up different use cases, see:
● Configure boundary clock with L2 transport method
● Configure boundary clock with IPv4 multicast transport method
● Configure boundary clock with IPv4 unicast transport method
● Configure end-to-end transparent clock
● Configure boundary clock with IPv4 unicast transport method and L3 VLAN
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System management