[mythtv-users] Fwd: Re: ntp stratum two time servers

[Rod Smith]

On Wednesday 30 April 2008 22:39:42 Tom Dexter wrote:
>
> I had the same four ntp statum two servers in ntp.conf on all three
> machines...servers I got here:

Instead of having multiple machines querying an NTP server off your local 
network, I recommend you have one local machine query an external NTP server 
and have the rest of your local machines query your first machine. That 
minimizes network traffic and the load on the off-site server. (Granted, even 
three extra machines' NTP traffic isn't all that huge, but every little bit 
helps, and if everybody did it this way, it could help a lot.) The loss of 
accuracy from the extra NTP "hop" won't be significant for most purposes, and 
certainly not for scheduling TV shows.

> I got around it by simply adding:
>
> server 0.pool.ntp.org
> server 1.pool.ntp.org
> server 2.pool.ntp.org
> server 3.pool.ntp.org
>
> ...to all of them.  Maybe that's what I should have done from the
> beginning.

The pool configuration is certainly a convenient way to do it, but not always 
optimal. I'm using an NTP server that's run by my ISP, thus (theoretically) 
minimizing network traffic and improving NTP performance. When given the 
choice, ntpd does sync to my ISP's server rather than others, so this seems 
to be a good choice for me.

> Is this a common problem?  Some of the servers I was using required
> notification, but I had in fact emailed them a long time ago when I
> started using them.

Public NTP servers do seem to come and go. Whether the servers you were using 
cut you off specifically or simply shut down public operations I don't know. 
It's certainly worth checking that your upstream NTP server(s) is/are still 
working from time to time.

-- 
Rod Smith