Re: NTP Synchronization

From: Thomwin Chen (thomwin_chen@yahoo.com)
Date: Mon Aug 15 2005 - 01:40:35 GMT-3

Mushtaq,
 
my guess for your NTP master config is like this :
 
ntp master
ntp authenticate
ntp trusted-key 1
ntp authentication-key 1 md5 groupstudy

Correct, it's working, because the ntp authentication-key 1 md5 groupstudy exist.
 
============================================
try this one (without ntp authentication-key 1 md5 groupstudy):
 
ntp master
ntp authenticate
ntp trusted-key 1
 
wait for a moment, show ntp status and debug ntp authentication, is it still syncrhonized ?
 
Rgds,
Thomwin
 

 

"mushtaq A. Khan" <mak.ccie2b@gmail.com> wrote:
Thomwin,

Thanks for you advise. Do you think that we need the following command
to enable ntp authentication and generate ntp keys on NTP master. Here
is the url for your reference. My configuration works fine after I
used these two commands.

ntp authenticate
ntp trusted-key 1

http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121cgcr/fun_c/fcprt3/fcd303.htm#wp1001202

Mushtaq

On 8/14/05, Thomwin Chen wrote:
> Mushtaq,
>
> CMIIW,
>
> I think the correct NTP authentication configuration is like this :
> at NTP client :
>
> ntp authenticate
> ntp authentication-key 1 md5 groupstudy
> ntp trusted-key 1
> ntp server 172.16.1.1 key 1
>
> at NTP master :
>
> ntp authentication-key 1 md5 groupstudy
> ntp master
>
> NTP authentication is used to authenticate the time source, not the
> recipient...
> and also NTP synchronization will synchronize gradually not instaneously
>
> Rgds,
> Thomwin
>
>
> "mushtaq A. Khan" wrote:
> All,
>
> Can anyone help in troubleshooting NTP synchronization? I'm trying to
> test NTP to see if NTP client synchronizes correctly with NTP server.
>
> I noticed that it works only when I try to change clock in client.
> The client correctly synchornizes with server. It does not work, when
> I change clock in Server. Can someone explain me the reason. Here is
> the configuration I'm used:
>
> Router(NTP Server):
> clock timezone CST -6
> clock summer-time CDT recurring
>
> ntp authentication-key 1 md5 01100F175804 7
> ntp authenticate
> ntp trusted-key 1
> ntp source Loopback0
> ntp master 3
>
>
> SW(NTP Client):
> clock timezone EST -5
> clock summer-time EDT recurring
> ntp authentication-key 1 md5 05080F1C2243 7
> ntp authenticate
> ntp trusted-key 1
> ntp clock-period 17179903
> ntp source Loopback0
> ntp server 132.1.4.4
>
> Thanks,
> M. A. Khan
>
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