NTP

[Geoff Shang]

Hi,

We have an array of devices and computers.  Two Linux machines, a win7 
box, an iMac, a Macbook Pro, an iPad, an iPad Mini, two iPods, three 
iPhones and two Nexus 7s.

We have Internet service from Bezeqint via Bezeq DSL.  We got a new router 
in February, which will become relevant shortly.

all our devices are configured to keep time synched automatically.  For 
the windows 7 machine, we installed a third-party time-keeping software 
instead o fallowing Windows to sync once a week.

all was working fine until I realised a couple of weeks ago that the 
windows machine was over 30 seconds slow.  Due to the time-keeping 
software installed, we were able to see that it hadn't managed to sync the 
time since 7 April.

I initially blamed Windows and the fact that I was running software that 
hadn't been updated in ten years.  But installing a windows port of NTP 
didn't fix things.

I then realised that my Linux machines weren't keeping time either.   They 
simply hadn't drifted as far, as Linux is better at keeping time.  The 
macs weren't either.

To cut a long lot of investigations short, I determined that I couldn't 
sync time using ntpd on port 123.  The only way I could get time sync to 
work was to use ntpdate with an unprivileged port.

I did some searching, and found a post (that I apparently didn't bookmark) 
that suggested that some sites block NTP traffic in order to prevent 
certain types of DOS attacks.  Users at such sites are expected to use NTP 
server(s) located within the network.

Since I tried a range of servers in a range of locations with no luck, I 
wondered if Bezeqint were doing the same thing.

I managed to find time.bezeqint.net but it doesn't seem to work either.

I called Bezeqint and had some difficulty explaining my problem to them in 
English.  When I did finally manage to get someone who knew what NTP is, 
they thought it might be  a problem with the router.  While this is 
possible, we got the router almost two months before the problem started.

I expect I might get a similar answer if I call them back again, and if I 
do call Bezeq about it, I expect them to blame Bezeqint and so-on.

Since nothing has changed in the last two weeks, I thought I might do 
better by asking here.

So I'm wondering:

1.  Is anyone else having this problem?

2.  Has anyone found a server that works?

3.  Any other ideas I've not thought of?

All our devices are now drifting at various rates and it's getting quite 
frustrating.

Geoff.