HPE FlexNetwork 10500 SERIES, Руководство по настройке

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Figure 34 NTP authentication
As shown in Figure 34 , NTP authentication works as follows:
1. The sender uses the MD5 algorithm to calculate the NTP message according to the key
identified by a key ID. Then, it sends the calculated digest together with the NTP message and
key ID to the receiver.
2. Upon receiving the message, the receiver performs the following actions:
a. Finds the key according to the key ID in the message.
b. Uses the MD5 algorithm to calculate the digest.
c. Compares the digest with the digest contained in the NTP message. If they are the same,
the receiver accepts the message. If they are different, the receiver discards the message.
NTP for MPLS L3VPN instances
On an MPLS L3VPN network, a PE that acts as an NTP client or active peer can synchronize with
the NTP server or passive peer in an MPLS L3VPN instance.
As shown in Figure 35 , users in VPN 1 and VPN 2 are connected to the MPLS backbone network
through provider edge (PE) devices. VPN instances vpn1 and vpn2 have been created for VPN 1
and VPN 2, respectively on the PEs. Services of the two VPN instances are isolated. Time
synchronization between PEs and devices in the two VPN instances can be realized if you perform
the following tasks:
•
Configure the PEs to operate in NTP client or symmetric active mode.
•
Specify the VPN instance to which the NTP server or NTP symmetric passive peer belongs.
Figure 35 Network diagram
For more information about MPLS L3VPN, VPN instance, and PE, see MPLS Configuration Guide .
Key value
Message
Sender
Message
Sends to the
receiver
Digest
Receiver
Compare
Compute the
digest
Compute the
digest
Digest
Key ID
Message
Digest
Key ID
Key value
CE
VPN 1
P
MPLS backbone
PE
PE
CE
CE
VPN 2
VPN 2
NTP server
Host
Host
CE
VPN 1
NTP symmetric
passive peer
NTP cliet/
symmetric active peer