On Sun, 24 Oct 2010, Brandon Kim wrote:
By local I meant in-house, on-site in our datacenter.
What do you think it means to have a NTP server in-house, on-site in your
datacenter? There all many different levels of NTP servers.
Putting some free software on a spare computer, and synchronizi
Complete WOB, but I whenever people start talking about NTP, I always
start trying to figure out how I could justify one of these for the data
center:
http://www.inovasolutions.com/network-clocks/products/analog-network-clocks.htm
(PoE, SNTP, ANALOG clock)
jms
--
Joel M Snyder, 1404 East Lin
On Sun, 24 Oct 2010, Cutler James R wrote:
In my experience, a reliable NTP peer group can be implemented on the
same set of boxes as DNS (bind, etc.) with little or no impact on DNS
performance. If you can count to four or more, you can make a reliable
peer group of time servers.
There are l
> Date: Sun, 24 Oct 2010 14:18:18 -0400
> From: David Andersen
> Subject: Re: NTP Server
(...)
> If you find yourself needing really precise time with good guarantees,
> you're not just talking about buying one GPS unit -- you can easily go
> down a rathole of finding multiple units with good hol
On Mon, 25 Oct 2010, Dobbins, Roland wrote:>
On Oct 25, 2010, at 3:48 AM, Matthew Petach wrote:
NTP can potentially be used as a DoS vector by your upstream clocks,
if you're not running your own.
+1
Also, if you experience a network partition event for any reason (DDoS
attack, backhoe attack
Nowadays is not that difficult to get off the shelf solutions for
different applications.
Just to point to one:
http://www.symmetricom.com/products/ntp-servers/ntp-network-appliances/
Regards
Jorge
Routers are not a good choice for time servers as it complicates configuration
and, to some extent, constrains deployment methodology for routers to be
effective with time service. We don't run DNS on routers, it is a service. Time
service via NTP is a service as well. The NTP daemon in a router
On Oct 25, 2010, at 3:48 AM, Matthew Petach wrote:
> NTP can potentially be used as a DoS vector by your upstream clocks, if
> you're not running your own.
+1
Also, if you experience a network partition event for any reason (DDoS attack,
backhoe attack, et. al.) which disrupts communications
>
> Coming across Phil Dykstra's paper from 1999 is what got me thinking
> about it (well, that and moving a lot of data between Europe and the
> West coast of the US).
>
> http://sd.wareonearth.com/~phil/jumbo.html
>
> http://staff.psc.edu/mathis/MTU/
>
>
Found more good information here:
h
Regarding leap seconds:
A modern OS kernel using the NTP daemon to control time will always experience
monotonic time. Negative leap seconds should result in the local clock slowing
slightly until the local time matches the NTP-derived time.
This is in strong contrast to what can happen when nt
Hi Sean:
By local I meant in-house, on-site in our datacenter. As far as what
applications could use our NTP service, I would
leave that up to each client and what they are running. For my own personal
purposes, it would just be for log purposes.
(error logs, syslogs, etc etc)
I have heard th
On 10/24/2010 7:37 PM, Peter Lothberg wrote:
>> acquired the time from the three stratum-1 clocks, they all poll each other
>> for the average.
>
> How many clocks/servers do you need to average from to knew that you
> are within say 1ms of UTC(nist)?
What type of evidence model do you need to p
On 10/24/2010 2:14 PM, Steven Hill wrote:
> On Sun, 24 Oct 2010, Christopher Morrow wrote:
>
>>> How do you knew that your local NTP server knew what time it is?
>>> (for sure)
Because you got the time service from an authoritative source who did
the rest of the work to make sure that the NTP ev
On Sun, 24 Oct 2010, Christopher Morrow wrote:
How do you knew that your local NTP server knew what time it is? (for sure)
this question is a trap.
Quite.
We had 2 HP 5071s,(+ several GPS standards) and at the time being the
definition of a second, either could be correct at any time. Whe
On Oct 24, 2010, at 4:48 PM, Matthew Petach wrote:
> On Sun, Oct 24, 2010 at 8:34 AM, Brandon Kim
> wrote:
>>
>> Hey guys:
>>
>> I wanted to open up this question regarding NTP server. I recalled someone
>> had created a posting of this quite awhile back.
>>> From a service provider/ISP stan
On Sun, Oct 24, 2010 at 8:34 AM, Brandon Kim wrote:
>
> Hey guys:
>
> I wanted to open up this question regarding NTP server. I recalled someone
> had created a posting of this quite awhile back.
> >From a service provider/ISP standpoint, does anyone think that having a
> >local NTP server is r
> From: Peter Beckman
> Sent: Sunday, October 24, 2010 11:33 AM
> To: North American Network Operators Group
> Subject: RE: NTP Server
>
> On Sun, 24 Oct 2010, George Bonser wrote:
> It sure would be nice if datacenter facilities offered an
independent
> NTP
> time source as a benefit for h
On Sun, 24 Oct 2010, Brandon Kim wrote:
1) How necessary do you believe in local NTP servers? Do you really
need the logs to be perfectly accurate?
2) If you do have a local NTP server, is it only for local internal
use, or do you provide this NTP server to your clients as an added
service?
3)
>
> I've had pretty good luck asking for higher MTU's on both customer and
> peering links. I'd say about an 80% success rate for dedicated
GigE's.
> It's generally not on the forms though, and sometimes you get what I
> consider weird responses. For instance I know several providers who
> won't
On Sun, 24 Oct 2010, George Bonser wrote:
The main reason for that is that the "free" servers won't remain "free"
if every single individual host on the Internet is hitting them. By
running your own internal servers a stratum down you offload that
traffic from the public servers and preserve th
> i would generally let customers chime off routers which are strat 2 or
> 3. if a customer has other needs, then they can deal. if they are
> really concerned, they should not bet on me anyway.
>
> > 3) If you do have a local NTP server, do you have a standby local
NTP
> >server or do you
On Oct 24, 2010, at 1:09 PM, Randy Bush wrote:
>> 1) How necessary do you believe in local NTP servers? Do you really
>> need the logs to be perfectly accurate?
>
> what is "perfectly accurate?" perfection is not very realistic. to
> what use do you put these logs? what precision and jitter
> Probably no reason at all, though probably little perceived benefit.
> 1492 is common enough that google/youtube already runs lower MTU's
just
> to avoid common broken PPPoE setups (which often could run higher MTU,
> but weren't configured that way).
I run into that already with people doing va
Looks like you have a pretty good setup. What vendor equipment are you using?
You can let me know offline so it doesn't
sound like you're advertising them
> Date: Sun, 24 Oct 2010 11:03:18 -0600
> From: br...@2mbit.com
> To: nanog@nanog.org
> Subject: Re: NTP Server
>
> On 10/24/10 9:3
Just for log purposes and possibly providing it to our clients as an added
service at no charge of course.
I don't see us needing to get very granular in the details of the times on the
logs
> Date: Sun, 24 Oct 2010 10:09:25 -0700
> From: ra...@psg.com
> To: brandon@brandontek.com
>
> acquired the time from the three stratum-1 clocks, they all poll each other
> for the average.
How many clocks/servers do you need to average from to knew that you
are within say 1ms of UTC(nist)?
-P
On 10/24/10 10:25 AM, John Kristoff wrote:
> The "perfect accuracy" of log files might be hard to justify and
> quantify.
more to the point what's the minimum resolution of a counter in a log
file, if it's 1s or 1ms it's a bit different than if it's 1us.
On Sun, Oct 24, 2010 at 1:24 PM, Joel Jaeggli wrote:
> On 10/24/10 10:20 AM, Christopher Morrow wrote:
>> On Sun, Oct 24, 2010 at 10:44 AM, Peter Lothberg wrote:
>>> How do you knew that your local NTP server knew what time it is? (for sure)
>>
>> this question is a trap.
>
> a man with one wat
On Sun, 24 Oct 2010 11:34:12 -0400
Brandon Kim wrote:
> I wanted to open up this question regarding NTP server. I recalled
> someone had created a posting of this quite awhile back.
> >From a service provider/ISP standpoint, does anyone think that
> >having a local NTP server is really necessary
On 10/24/10 10:20 AM, Christopher Morrow wrote:
> On Sun, Oct 24, 2010 at 10:44 AM, Peter Lothberg wrote:
>>> 1) How necessary do you believe in local NTP servers? Do you really need th=
>>> e logs to be perfectly accurate?
>>> 2) If you do have a local NTP server=2C is it only for local internal
James --
Well said. I was going to submit the exact same thing. This is what we we
do at my company and it works extremely well - we only use three stratum-1
time servers, and three internal servers to go get the time from the three
externals, via a one-to-one correspondence. Once all three int
On 10/24/2010 12:29 PM, Brandon Kim wrote:
I guess what I'm trying to understand is, is having your own NTP server just a
luxury?
I personally would like to have my own, I just need to pitch its advantages to
my company. Unless everyone here on the NANOG group
clearly spells it out to me that
In a message written on Sun, Oct 24, 2010 at 11:34:12AM -0400, Brandon Kim
wrote:
>From a service provider/ISP standpoint, does anyone think that having a local
>NTP server is really necessary?
Do you provide NTP to your customers?
If you do there is probably an obligation there to make a reas
On Sun, Oct 24, 2010 at 10:44 AM, Peter Lothberg wrote:
>> 1) How necessary do you believe in local NTP servers? Do you really need th=
>> e logs to be perfectly accurate?
>> 2) If you do have a local NTP server=2C is it only for local internal use=
>> =2C or do you provide this NTP server to your
More than likely, it's more important that all your machines are synced
accurately in time to each other, vs. a wider sync range that's
statistically closer to the 'real' value.
-Jack Carrozzo
On Sun, Oct 24, 2010 at 1:09 PM, Randy Bush wrote:
> > 1) How necessary do you believe in local NTP se
Time Service is more complicated than just having a single NTP server. But it
can be useful and is not really a luxury.
Two primary reasons for local time service are to reliably serve a network that
is relatively or completely isolated from the general internet, and, to provide
a local time so
> 1) How necessary do you believe in local NTP servers? Do you really
>need the logs to be perfectly accurate?
what is "perfectly accurate?" perfection is not very realistic. to
what use do you put these logs? what precision and jitter are required
for that use?
imiho, if you are just comp
In a message written on Sun, Oct 24, 2010 at 11:09:28AM -0500, Jack Bates wrote:
> variety of tags/tunnels/etc by the time it gets to the cell phone. It
> cracks me up that SONET interfaces default 4470, and ethernet still
> defaults to 1500. I've yet to see an MTU option in standard circuit
>
On 10/24/10 9:34 AM, Brandon Kim wrote:
I wanted to open up this question regarding NTP server. I recalled
someone had created a posting of this quite awhile back.
From a service provider/ISP standpoint, does anyone think that
having a local NTP server is really necessary?
It may not be nec
On 10/24/2010 09:26, Brandon Kim wrote:
>
> Wow that is amazing and quite impressive that you even run the antenna
> linesinteresting..do you have to pay for the GPS service?
>
Make your own simple GPS NTP clock source:
http://www.satsignal.eu/ntp/FreeBSD-GPS-PPS.htm
~Seth
I guess what I'm trying to understand is, is having your own NTP server just a
luxury?
I personally would like to have my own, I just need to pitch its advantages to
my company. Unless everyone here on the NANOG group
clearly spells it out to me that it's a luxury.
I can see it as an added ser
Wow that is amazing and quite impressive that you even run the antenna
linesinteresting..do you have to pay for the GPS service?
> Subject: Re: NTP Server
> To: brandon@brandontek.com
> From: jkre...@usinternet.com
> Date: Sun, 24 Oct 2010 15:52:03 +
>
> Internet ntp is not
On 25/10/10 2:55 AM, Eugen Leitl wrote:
>
> For those you care about that:
>
> http://leapsecond.com/time-nuts.htm
Wow ... that's a lot more effort than I'm willing to put in on a time
server.
Regards,
Ben
signature.asc
Description: OpenPGP digital signature
On 10/24/2010 5:05 AM, George Bonser wrote:
And speaking of changing MTU, is there any reason why private exchanges
shouldn't support jumbo frames? Is there any reason nowadays that things
that are ethernet end to end can't be MTU 9000 instead of 1500? It
certainly would improve performance and
On Mon, Oct 25, 2010 at 02:51:24AM +1100, Ben McGinnes wrote:
> > How do you knew that your local NTP server knew what time it is? (for sure)
>
> By polling as many stratum 1 and 2 time servers as possible. Having
> your own stratum 2 server(s) beats nebulous NTP servers out in the big
> bad In
On 24/10/10 5:44 PM, Peter Lothberg wrote:
>
> How do you knew that your local NTP server knew what time it is? (for sure)
By polling as many stratum 1 and 2 time servers as possible. Having
your own stratum 2 server(s) beats nebulous NTP servers out in the big
bad Internet every time.
Regard
> 1) How necessary do you believe in local NTP servers? Do you really need th=
> e logs to be perfectly accurate?
> 2) If you do have a local NTP server=2C is it only for local internal use=
> =2C or do you provide this NTP server to your clients as an added service?
> 3) If you do have a local NTP
Hey guys:
I wanted to open up this question regarding NTP server. I recalled someone had
created a posting of this quite awhile back.
>From a service provider/ISP standpoint, does anyone think that having a local
>NTP server is really necessary?
I've asked some of my fellow engineers at work
On Oct 24, 2010, at 6:48 AM, Leo Bicknell wrote:
> In a message written on Sat, Oct 23, 2010 at 05:23:14PM -0700, Owen DeLong
> wrote:
>> On Oct 23, 2010, at 8:03 AM, Carlos Martinez-Cagnazzo wrote:
>>> On Fri, Oct 22, 2010 at 11:38 AM, Leo Bicknell wrote:
There are some folks (like me) wh
In a message written on Sat, Oct 23, 2010 at 05:23:14PM -0700, Owen DeLong
wrote:
> On Oct 23, 2010, at 8:03 AM, Carlos Martinez-Cagnazzo wrote:
> > On Fri, Oct 22, 2010 at 11:38 AM, Leo Bicknell wrote:
> >> There are some folks (like me) who advocate a DHCPv6 that can convey
> >> a default gatew
>
> What would be nice would be if we changed the semantics a bit and made
> it 16+48+64 where the first 16 of the dest+source could be
re-assembled
> into the destination ASN for the packet and the remaining 48
identified
> a particular subnet globally with 64 for the host. Unfortunately, that
>
>
> What would be nice would be if we changed the semantics a bit and made
> it 16+48+64 where the first 16 of the dest+source could be
re-assembled
> into the destination ASN for the packet and the remaining 48
identified
> a particular subnet globally with 64 for the host. Unfortunately, that
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