Protocols And Standards; Configuration Restrictions And Guidelines; Configuration Task List - HPE FlexNetwork 5510 HI Series Network Management And Monitoring Configuration Manual

The device supports multiple VPN instances only when it functions as a CE in an MPLS VPN.
For more information about MPLS L3VPN, VPN instance, and PE, see MPLS Configuration Guide.
As Figure 8
through provider edge (PE) devices, and services of the two VPNs are isolated. If you configure the
PEs to operate in NTP client or symmetric active mode, and specify the VPN to which the NTP server
or NTP symmetric passive peer belongs, the time synchronization between PEs and devices of the
two VPNs can be realized.
Figure 8 Network diagram
VPN 1
Host
VPN 2
Host

Protocols and standards

•
RFC 1305, Network Time Protocol (Version 3) Specification, Implementation and Analysis
•
RFC 5905, Network Time Protocol Version 4: Protocol and Algorithms Specification

Configuration restrictions and guidelines

Follow these restrictions and guidelines when you configure NTP:
•
You cannot configure both NTP and SNTP on the same device.
•
Do not configure NTP on an aggregate member port.
•
The NTP service and SNTP service are mutually exclusive. You can only enable either NTP
service or SNTP service at a time.
•
To ensure time synchronization accuracy, do not specify more than one reference source.
Doing so might cause frequent time changes or even synchronization failures.
•
Make sure you use the clock protocol command to specify the time protocol as NTP. For more
information about the clock protocol command, see Fundamentals Command Reference.

Configuration task list

Tasks at a glance
(Required.)
(Required.) Perform one or both of the following tasks:
•
Configuring NTP association mode
•
Configuring the local clock as a reference source
shows, users in VPN 1 and VPN 2 are connected to the MPLS backbone network
CE
NTP cliet/
symmetric active peer
PE
CE
Enabling the NTP service
PE
P
MPLS backbone
12
VPN 2
NTP server
CE
VPN 1
NTP symmetric
passive peer
CE