CCNA LAB35: Configuring a Router as an NTP Client

小乔

Lab Objective:
The objective of this lab exercise is for you to learn and understand how to configure the Cisco router to access the time from an NTP server.

Lab Purpose:
NTP is an important tool used by Cisco equipment to ensure that devices share a consistent time. It is also used to add accurate timestamps to debug messages.

Certification Level:
This lab is suitable for CCENT and CCNA certification exam preparation.

Lab Difficulty:
This lab has a difficulty rating of 5/10.

Readiness Assessment:
When you are ready for your certification exam, you should complete this lab in no more than 5 minutes.

IMPORTANT NOTE: In order to test NTP, you will need to be connected to an actual NTP server that you probably will not have with a home lab or remote rack.


Lab Topology:
Please use the following topology to complete this lab exercise:



Task 1:
Configure the hostname on router R1 as illustrated in the topology.

Task 2:
Set the clock manually to any time zone and time of your choice.


Task 3:
Configure R1 to access two NTP servers. Use any IP addresses you wish.

Task 4:
Verify your NTP configurations with the appropriate show commands.

Configuration and Verification
Task 1:
For reference information on configuring hostnames, please refer to earlier labs.

Task 2:
R1#clock set 15:10:30 15 June 2014
R1#
*Jun 15 15:10:30.000: %SYS-6-CLOCKUPDATE: System clock has been updated from 00:02:21 UTC Fri Mar 1 2002 to 15:10:30 UTC Sun Jun 15 2014, configured from console by console.
R1#show clock
15:10:35.375 UTC Sun Jun 15 2014
Task 3:
Some of these commands won’t work with Packet Tracer.


R1(config)#ntp server 10.1.1.1 prefer
R1(config)#ntp server 172.16.1.1
R1(config)#
R1(config)#end
Task 4:
R1#show ntp associations

address     ref clock     st  when  poll reach  delay  offset   disp
~10.1.1.1   0.0.0.0       16  -     64   0      0.0    0.00     16000.
~172.16.1.1 0.0.0.0       16  -     64   0      0.0    0.00     16000.
* master (synced), # master (unsynced), + selected, - candidate, ~ configured

R1#show ntp status        
Clock is unsynchronized, stratum 16, no reference clock
nominal freq is 250.0000 Hz, actual freq is 250.0000 Hz, precision is 2**18
reference time is 00000000.00000000 (00:00:00.000 UTC Mon Jan 1 1900)
clock offset is 0.0000 msec, root delay is 0.00 msec
root dispersion is 0.00 msec, peer dispersion is 0.00 msec
R1#
You can add another router and configure it as an NTP server with the command below:

R1(config)#ntp master ?
<1-15>  Stratum number
<cr>

来源: CCNA LAB29: Debugging and Verifying RIP Version 2 Updates
来源: CCNA LAB30:  Passive Interfaces for RIPv2 Updates
来源: CCNA LAB31: RIPv2 Split Horizon
来源: CCNA LAB32: Configuring the Cisco IOS DHCP Server
来源: CCNA LAB33: Troubleshooting and Configuring DHCP (Client-Server Router-Based)
来源: CCNA LAB34: 配置DHCP Relay

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