Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

New Member

NTP Issue


I am needing a NTP Server in "Windows Server" in such a way to use the NTP in my infrastructure with cisco routers with authentication supports.

I'm testing with "NTP 4.X". The application works without authentication but I can not run with authentication required.

Someone has already gone through this need?

Help me please.

Edgar Servín

Everyone's tags (1)
New Member

NTP Issue

Have you tried Meinberg NTP?? It essentially is linux ntp server for windows.

New Member

NTP Issue

Hi Tkatsiaounis,

Meinberg NTP 4.X is the software I am using.

Its documentation is not very understandable to me.

I can't make it work correctly with authentication.

I set up in my "Cisco router" with the command "ntp authenticate". The "NTP server" continues to operate but by entering the command: "show ntp asso detail" don't shows me the message "authenticated".

Do you have a sample configuration? Could you guide me in my setup, please?

New Member

NTP Issue

Hi Leo,

The "Windows Server" uses the "SNTP / NTP" and does not work with Cisco IOS NTP.


Hall of Fame Super Gold

NTP Issue

Ok then.  It's either you let the routers go out to the net for an authoritative NTP source or you can purchase a "true" NTP server.

When I mean a "true" NTP server, it's not the kind which has to go out to the internet and to get an authoritative source.  I mean the ones with built-in GPS receivers. 

New Member

NTP Issue

I think it's very difficult to add a GPS for NTP on our infrastructure.

Although I think would be good.

I need an example of configuration of meinberg NTP.


Hall of Fame Super Gold

NTP Issue

You don't need to install the NTP server inside the DC.  Find a cabinet that's closest to the ceiling and it'll do fine.  The servers normally come with a magnetic antenna.

New Member

NTP Issue

Hi Leo,

We didn't planning an acquisition of a GPS for NTP.

Just for that I'm looking for the solution through the Meinberg NTP.

It is not necessary for our infrastructure a NTP server so specialized.

Only one that allows us to maintain uniform time in the network of PCs and routers, that provides NTP authentication.


Re: NTP Issue

Hello, I was looking for a solution between many devices on my networks, finally I find a option, use a border router like a NTP Proxy.

I try many setting between MS Windows like a NTP Server over other devices no PCs, in my case don't work, but I try with a Router like NTP Server, perfect work.

Other good practice is send params over DHCP sending to the clients option 42.

Let the commands and screens:

NTP Server ~ Client on the Router:

ntp logging

ntp clock-period 17179973

ntp master

ntp update-calendar

ntp server source FastEthernet1

ntp server source FastEthernet0

Config NTP on DHCP Server:

ip dhcp pool LAN


   update dns both

   domain-name example.ext



   netbios-node-type b-node

   option 42 ip

   lease 0 0 5

   update arp

Analyzing DHCP behavior with Wireshark:

Set on MS Windows:

Depend of MS Windows behaviour, Windows Domain (atomically) Vs Workgroup (set in MS Clients IP or Router FQDN Master NTP)