From: Anderson Mota Alves (mota_anderson@hotmail.com)
Date: Thu Feb 09 2006 - 08:35:09 GMT-3
Hi,
Yes I really meant that, when you configure R1 as the MASTER with a
stratum of 2 the clients will be receiving it as one hop away (NTP
stratum concept) so it will increment 1 so it will be 3 on the clients
side. So you don't need to configure stratum values on the client sides
only a value on the server side, also as you described the lower the
stratum the better it will be I suggest you to always use authentication
so this way you will ensure that in case someone put a router with lower
stratum value your clients won't synchronize with this new router on the
network.
Also another concept to be aware of, is that if they ask you to configure
authentication and the clients should synchronize with the server after
authentication process that is a tricky thing you need to be aware of
here, don't forget to configure the "ntp trusted-key" on the clients
otherwise it will authenticate with server but won't synchronize telling
in the command "show ntp association detail" master as insane.
NTP uses the concept of a "stratum" to describe how many NTP "hops" away
a machine is from an authoritative time source. A "stratum 1" time server
typically has an authoritative time source (such as a radio or atomic
clock, or a GPS time source) directly attached, a "stratum 2" time server
receives its time via NTP from a "stratum 1" time server, and so on.
There is a really good example on the internetworkexpert website:
http://internetworkexpert.com/resources/01700369.htm
I hope it helps,
Andy
--------------------------------------------------------------------
From: sameer azam <sameer.azam@gmail.com>
To: Anderson Mota Alves <mota_anderson@hotmail.com>
Subject: Re: NTP Quesion
Date: Thu, 9 Feb 2006 14:33:44 +0400
hi,Do u mean that when u configure R1 as the MASTER with a stratum of
2 then automatically other ( SW & R4) will set their stratum value to
3. See i understand the stratum concept and that is no more than this
that lower the value better the stratum is. but when when asked to
configure the A SECIFIC Stratum value on R4 & Sw do u need to
configure that or not?and also there is no NTP MASTER command on the
CAT 3550. so in this what should be the correct answer. Regards
On 2/9/06, Anderson Mota Alves <mota_anderson@hotmail.com> wrote:
Hi Sameer,
Since you need to have the clients with a stratum of 3 in order
to accomplish that you need to configure the server with a
stratum of 2, so in this case the clients will be getting the
stratum with a value of 3.
Solution:
SW: loopback 0's SW: 12.12.7.7
ntp server 12.12.1.1
ntp source loopback 0
R4: loopback 0's R4: 12.12.4.4
ntp server 12.12.1.1
ntp source loopback 0
R1: (the server) Loopback 0's R1: 12.12.1.1
ntp master 2
ntp source loopback 0
Note that I haven't configured any stratum value on SW since this
router will
be getting this value from the server (R1)
If you have a way to set this up please do it and then let me
know if everything worked fine.
Regards,
Andy
------------------------------------------------------------
From: Ivan <ivan@iip.net>
Reply-To: Ivan <ivan@iip.net>
To: ccielab@groupstudy.com, sameer azam <sameer.azam@gmail.com>
Subject: Re: NTP Quesion
Date: Thu, 9 Feb 2006 11:56:47 +0300
>lake(config)#ntp master ?
> <1-15> Stratum number
>
>
> > The topology is like follows;
> >
> > SW
> >
> >
> >
R1______---_______R4
> >
> > The link between R1 & Sw is Ethernet connection.
> > The link between R1 & R4 is Frame-Relay Connection.
> >
> > The QUESTION IS;
> >
> > You need to configure the R4 & SW for STRATUM 3
> > Both of R4 & SW should get get their time clock from the
R1.
> >
> > How would you do this?
> >
>
>--
>Ivan
>
>_______________________________________________________________________
>Subscription information may be found at:
>http://www.groupstudy.com/list/CCIELab.html
This archive was generated by hypermail 2.1.4 : Wed Mar 01 2006 - 11:28:17 GMT-3