Hi,

We are planing to deploy Network Time Server in our Organization.

According to the architecture , Stratum 2 server will be responsible to 
provide correct time to Stratum 3 server and client ( Other servers) will 
synchronize with Stratum 3 server for obtaining correct time. Stratum 2 
server will synchronize with Stratum 1  server. 

We will use NTP 4.2.6p3 

Is it mandatory to open UDP port 123  between Stratum 2 and Stratum 3 
server also between Stratum 3 and Client Machine for time synchronization? 


Can we use any customized port instead of UDP 123 for time 
synchronization? 

Please suggest. 

Thanks and Regards, 
Chandan Laskar 
2nd Floor Data Center, ITC Center, 
4, Russel Street, Kolkata - 700 016 
Phone:(033)-40029000 Extn.: 3944 
             (0)-9830057396 (M) 

Please visit us at www.itcportal.com
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Companies.

Chandan Laskar wrote:
>
> Hi,
>
> We are planing to deploy Network Time Server in our Organization.
>
> According to the architecture , Stratum 2 server will be responsible to
> provide correct time to Stratum 3 server and client ( Other servers) will
> synchronize with Stratum 3 server for obtaining correct time. Stratum 2
> server will synchronize with Stratum 1  server.
>
> We will use NTP 4.2.6p3
>
> Is it mandatory to open UDP port 123  between Stratum 2 and Stratum 3
> server also between Stratum 3 and Client Machine for time synchronization?
>
>
> Can we use any customized port instead of UDP 123 for time
> synchronization?

You _can_ change the port number, but only by patching and costum 
compiling your own version of the NTP source code.

I.e. the answer is effectly: "No, you cannot change: Port 123 is the 
time sync port!"

Terje

-- 
- <Terje.Mathisen at tmsw.no>
"almost all programming can be viewed as an exercise in caching"

On 2011-02-09, Chandan Laskar <Chandan.Laskar@itc.in> wrote:
>
> Hi,
>
> We are planing to deploy Network Time Server in our Organization.
>
> According to the architecture , Stratum 2 server will be responsible to 
> provide correct time to Stratum 3 server and client ( Other servers) will 
> synchronize with Stratum 3 server for obtaining correct time. Stratum 2 
> server will synchronize with Stratum 1  server. 
>
> We will use NTP 4.2.6p3 
>
> Is it mandatory to open UDP port 123  between Stratum 2 and Stratum 3 
> server also between Stratum 3 and Client Machine for time synchronization? 

Maybe if you told us what your concern was, rather than asking us if the
solution to your concern was viable, someone could give you good advice. 
>
>
> Can we use any customized port instead of UDP 123 for time 
> synchronization? 

Why would you want to? 



> ******************************************************************************
> This Communication is for the exclusive use of the intended recipient (s) and shall
> not attach any liability on the originator or ITC Ltd./its Subsidiaries/its Group 
> Companies. If you are the addressee, the contents of this email are intended for your 
> use only and it shall not be forwarded to any third party, without first obtaining 
> written authorisation from the originator or ITC Ltd./its Subsidiaries/its Group 
> Companies. It may contain information which is confidential and legally privileged
> and the same shall not be used or dealt with by any third party in any manner 
> whatsoever without the specific consent of ITC Ltd./its Subsidiaries/its Group 
> Companies.
And again, attaching this kind of disclaimer to a netnews post destroys
any legal force it might have had when attached to a valid confidential
email.

On Wed, Feb 9, 2011 at 1:20 AM, Chandan Laskar <Chandan.Laskar@itc.in> wrot=
e:
>
> Hi,
>
> We are planing to deploy Network Time Server in our Organization.
>
> According to the architecture , Stratum 2 server will be responsible to
> provide correct time to Stratum 3 server and client ( Other servers) will
> synchronize with Stratum 3 server for obtaining correct time. Stratum 2
> server will synchronize with Stratum 1 =A0server.
>
> We will use NTP 4.2.6p3
>
> Is it mandatory to open UDP port 123 =A0between Stratum 2 and Stratum 3

Between servers that you control you had build ntpd to use any port
you like.  But of course to comunicate with servers outside your
control you have touse the agreed to port.   At soe point to will need
a ntpd server tat faces both ways to "pool" servers on the Internet on
port 123 and to your internal servers.  This server will need to
listen on bth 123 and your custom port number.

Now the question is "Why?"  what is the reason for not using 123?

Broadcast might solve this problem.  If you can use broadcast then you
are not using 123.  But again what is the big picture, what is the
problem to be solved by all o this?
-- =

=3D=3D=3D=3D=3D
Chris Albertson
Redondo Beach, California

On 2011-02-11, Chris Albertson <albertson.chris@gmail.com> wrote:
> On Wed, Feb 9, 2011 at 1:20 AM, Chandan Laskar <Chandan.Laskar@itc.in> wrote:
>>
>> Hi,
>>
>> We are planing to deploy Network Time Server in our Organization.
>>
>> According to the architecture , Stratum 2 server will be responsible to
>> provide correct time to Stratum 3 server and client ( Other servers) will
>> synchronize with Stratum 3 server for obtaining correct time. Stratum 2
>> server will synchronize with Stratum 1 �server.
>>
>> We will use NTP 4.2.6p3
>>
>> Is it mandatory to open UDP port 123 �between Stratum 2 and Stratum 3

[snip]

> ... "Why?"  what is the reason for not using 123?

You were not clear about who controls which server(s).

> Broadcast might solve this problem.  If you can use broadcast then you
> are not using 123.

All ntpd modes use UDP/123 as the source and destination address.

Broadcast clients listen to the broadcast address to discover servers.

Unicast clients poll a time server at a designated IP address.

-- 
Steve Kostecke <kostecke@ntp.org>
NTP Public Services Project - http://support.ntp.org/

>> We are planing to deploy Network Time Server in our Organization.
>>
>> According to the architecture , Stratum 2 server will be responsible to
>> provide correct time to Stratum 3 server and client ( Other servers) will
>> synchronize with Stratum 3 server for obtaining correct time. Stratum 2
>> server will synchronize with Stratum 1  server.
>>
>> We will use NTP 4.2.6p3
>>
>> Is it mandatory to open UDP port 123  between Stratum 2 and Stratum 3
>> server also between Stratum 3 and Client Machine for time synchronization?
>>
>>
>> Can we use any customized port instead of UDP 123 for time
>> synchronization?
>
> You _can_ change the port number, but only by patching and costum  
> compiling your own version of the NTP source code.

Or put omnisync in between.
omnisync -M sntp -h host:port

http://www.vanheusden.com/time/omnisync/


Folkert

-- 
----------------------------------------------------------------------
Phone: +31-6-41278122, PGP-key: 1F28D8AE, www.vanheusden.com