Solved

Help with NTP on a new Cisco 3850 switch

Posted on 2014-10-27
7
1,629 Views
Last Modified: 2014-11-04
Hello All,
Hello All,

We put in a new Cisco 3850 this last weekend.  The switch is working fine except for NTP.  The new switch is supposed to be the NTP server for the network.  However, other switches and servers are not syncing with the new switch, and I'm not seeing what the issue is.  The new switch is syncing with the atomic clock fine.  Below is the configuration for NTP on the new switch.


SW3850#show run | i ntp
ntp source Vlan2
ntp access-group peer 10
ntp access-group serve-only 20
ntp master
ntp server 192.43.244.18 source Vlan2
ntp server 132.163.4.101 prefer source Vlan2
ntp server 132.163.4.102 source Vlan2
ntp server 132.163.4.103 source Vlan2


Regards,
Nick Dalmolin
0
Comment
Question by:ndalmolin_13
  • 4
  • 2
7 Comments
 
LVL 45

Expert Comment

by:Craig Beck
ID: 40407922
Can you post ACL 10 and 20 too please?
0
 
LVL 12

Accepted Solution

by:
Fidelius earned 500 total points
ID: 40407927
Hello,

Remove command ntp master. By default, if this switch is configured with the external NTP server, it will act as NTP Master for the rest of devices in your network which point to it as NTP server.

Here is explanation of command:
http://www.cisco.com/c/en/us/td/docs/ios/12_2/configfun/command/reference/ffun_r/frf012.html#wp1123474

Regards!

Fidelius
0
 
LVL 45

Expert Comment

by:Craig Beck
ID: 40408484
Fidelius is right, but that wont 'stop' clients connecting to the switch as a ntp client.  It just forces the switch to give the time to clients from its own hardware clock.
0
Threat Intelligence Starter Resources

Integrating threat intelligence can be challenging, and not all companies are ready. These resources can help you build awareness and prepare for defense.

 
LVL 12

Expert Comment

by:Fidelius
ID: 40409356
I agree. But ntp master command sometimes makes trouble. As it is not needed in this case, it is better to remove it, before further troubleshoot
0
 
LVL 45

Expert Comment

by:Craig Beck
ID: 40409413
The only trouble I've ever had with ntp master is when you have more than one in your network.  This can cause stratum issues and loss of sync.  I do agree though, it's not required - I was just mentioning that it won't stop devices from syncing as clients.
0
 
LVL 1

Author Closing Comment

by:ndalmolin_13
ID: 40421700
Thanks all for the help.  Apologies for not getting back to this sooner.  I was out of the office last week.
0
 
LVL 45

Expert Comment

by:Craig Beck
ID: 40421850
So did the chosen answer work?
0

Featured Post

6 Surprising Benefits of Threat Intelligence

All sorts of threat intelligence is available on the web. Intelligence you can learn from, and use to anticipate and prepare for future attacks.

Join & Write a Comment

Suggested Solutions

Title # Comments Views Activity
Cisco MSRP pricing 5 45
Weird MAC Flapping seen on wireless 5 54
cisco switch stacking 6 34
EIGRP on point-to-point vlan 14 24
The worst thing when starting a new job is when the previous Network Administrator left behind no documentation. How do you get into the devices? If you've been in this situation or just accidently mistyped your password, this article will hopefully…
I see many questions here on Experts Exchange regarding switch port configurations and trunks. This article is meant for beginners in the subject to help to get basic knowledge about Virtual Local Area Network (VLAN (http://en.wikipedia.org/wiki/Vir…
In this tutorial you'll learn about bandwidth monitoring with flows and packet sniffing with our network monitoring solution PRTG Network Monitor (https://www.paessler.com/prtg). If you're interested in additional methods for monitoring bandwidt…
You have products, that come in variants and want to set different prices for them? Watch this micro tutorial that describes how to configure prices for Magento super attributes. Assigning simple products to configurable: We assigned simple products…

757 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

22 Experts available now in Live!

Get 1:1 Help Now