ben slimup wrote:
thanks all,
let s say, i have one site in california and another one in new york.
all clients are independent to each other and connected to adsl.
all clients are spread out all over the internet.
six ntp servers are located in each site ( CA and NY)
and need to connect the internet to send time to all clients.
If your clients are on the internet, then you are _NOT_ using private
addresses for them!
(Or is this a corporate VPN connected via private ADSL links?)
lets say that i have control to clients config file meaning that i will config
4 external ip address.
how servers will send the ntp traffic over the internet to synch all clients?
Servers never send out traffic, they just reply to requests...
To Terje
i m not an ISP
what kind of info you will need?
Types of IP addresses available for both servers and clients.
Can clients and/or servers communicate with both private and public
addresses?
Terje
Regards ;)
From: "terje.mathisen at tmsw.no"@ntp.org
To: questions@lists.ntp.org
Date: Thu, 22 Dec 2011 19:09:07 +0100
Subject: Re: [ntp:questions] ntp server pool advice
ben slimup wrote:
Hi Terje,
if i do not use nat how can i route private adresse to internet ?, i
do not want to use ipv6.
What is your setup?
Are you an ISP, or do you have some control over the client configuration?
Assuming you are using private addresses for all your clients, by far
the simplest setup would be to setup your 4-6 private NTP servers in the
same private address range, and keep all communication private.
If I were you I would allow your internal servers to use multiple
external (pool.ntp.org?) as backup for your GPS sources.
also i m planning to 2 boxes with 3 card on each site, how can i load
balance between site if i m do not use round robin?
Proper NTP (i.e. if you control the clients!) is to use multiple (at
least 4!) servers from each client.
If you just have to publicize an official server list, then I would use
the same setup as the ntp pool, i.e. ntp.yourdomain.com would return
multiple addresses, probably in random or round robin order.
We need more detail to help you!
Terje
Thank for your support
From: "terje.mathisen at tmsw.no"@ntp.org To:
questions@lists.ntp.org Date: Thu, 22 Dec 2011 12:44:07 +0100
Subject: Re: [ntp:questions] ntp server pool advice
ben slimup wrote:
Thank for prompt answer Chris,
Unfortunately, this ntp network should give time to specific
clients devices and not anyone on the public network.
according to your advice, better not using load balancer, thats
good how to load balance between ntp server if i do not use round
robin? if all client choosing the same server then the ntp server
will be overload. is it a problem if for example client 1 poll
or synch with server 1 , and then with server 2 , etc...? or udp
roundtrip comes each time from different ntp server? how many ntp
servers should be needed to handle that much request knowing that
each card handle 10,000 request per sec?
First, each client should have at least 4 configured servers, so
you can use the same ntp.conf file for all of them.
Second, if you really can handle 10K requests/second per card, then
that means that you can handle 640K clients per card, with
worst-case polling.
I.e. servers capable of 10K/second should handle your expected load
just fine, even though a proper (FreeBSD-based) 1U server with a
GPS will serve even more clients with better time performance.
Terje
much appreciate your expertize
cheers
From: albertson.ch...@gmail.com Date: Wed, 21 Dec 2011
19:43:53 -0800 Subject: Re: [ntp:questions] ntp server pool
advice To: slimu...@hotmail.com
On Wed, Dec 21, 2011 at 5:07 PM, ben
slimup<slimu...@hotmail.com> wrote:
Dear all,
Thank you very much for support,
i do not have 1000,000 client, i need those ntp servers to
serve a load between 100000 to 1000000 clients over a public
network with an accuracy of 100ms
those clients will use dns round robin to resolve 4 external
ip, 2 IPs on each site. i have 4 servers with 4 ntp server
slot card each ( meinberg M900) 1 ntp server card can support
10,000 request.
First off the good news. 100ms is an "easy" spec to meet you
can do this without a lot of effort.
Don't let the outside world "see" your meinberg servers.
Build out a layer of "statum 2" servers and expose those to
your clients. 1M clients is a lot for the little 386 class CPU
that is in the meinberg box.
I still don't understand, Why do all those NTP clients need to
go to your NTP servers. Why can't they use any they like?
Are your servers doing something special?
Also know that EACH client needs to be configured to see
multiple NTP servers. practically three servers is a minimum
but others will argue for more for five
A would not use load balancing for NTP servers. With NTP it
does not matter at all if a server crashes. The clients are
all configure to use five servers and if one crashes they will
do fine using four. If you expose four, large robust servers
one on each of your four IP addresses then you will be fine,
even if one fails you will be fine. The clients will notice the
failure and continue on using the remaining three.
I technical question for the list: Would Round Robin load
balancing even work. I think it would introduce so much jitter
the server would be usless. I think you have to be sure that
each time a client pools a server at a given IP address it
polls the same physical server.
Chris Albertson Redondo Beach, California
-- -<Terje.Mathisen at tmsw.no> "almost all programming can be
viewed as an exercise in caching"
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