Cisco AP775A - Nexus Converged Network Switch 5010 Configuration Manual page 289

Chapter 12 Initial Configuration
S e n d d o c u m e n t a t i o n c o m m e n t s t o m d s f e e d b a c k - d o c @ c i s c o . c o m
Tip If an active server fails, a configured peer helps in providing the NTP time. Provide a direct NTP server
association and configure a peer to ensure backup support if the active server fails.
If you only configure a peer, the most accurate peer takes on the role of the NTP server and the other
peer(s) acts as a peer(s). Both machines end at the right time if they have the right time source or if they
point to the right NTP source.
NTP Configuration Guidelines
The following guidelines apply to all NTP configurations:
•
•
•
Not even a server down time will affect well-configured switches in the network.
network with two NTP stratum 2 servers and two switches.
Figure 12-4
Stratum-2
Server-1
In this configuration, the switches were configured as follows:
•
•
•
•
OL-17256-03, Cisco MDS NX-OS Release 4.x
You should have a peer association with another switch only when you are sure that your clock is
reliable (which means that you are a client of a reliable NTP server).
A peer configured alone takes on the role of a server and should be used as backup. If you have two
servers, then you can have several switches point to one server, and the remaining switches to the
other server. Then you would configure peer association between these two sets. This forces the
clock to be more reliable.
If you only have one server, all of the switches should have a client association with that server.
NTP Peer and Server Association
From lower stratum
server-1
Peer association
Server
association
Peer association
Switch-1
Stratum 2 Server 1
– IPv4 address–10.10.10.10
Stratum–2 Server-2
IPv4 address–10.10.10.9
–
Switch 1 IPv4 address–10.10.10.1
Switch 1 NTP configuration
NTP server 10.10.10.10
–
From lower stratum
server-2
Stratum-2
Server-2
Server
association
Switch-2
Cisco MDS 9000 Family Fabric Manager Configuration Guide
NTP Configuration
Figure 12-4 displays a
12-5