[ntp:questions] Re: peer trouble ? reach going down

David Schwartz davids at webmaster.com
Thu Aug 7 20:02:21 UTC 2003


"David J Taylor" <david-taylor at blueyonder.co.uk> wrote in message
news:APqYa.1175$HB4.10345599 at news-text.cableinet.net...

> Interesting - I have seen something similar on my own LAN, where there is
> most unlikely to be packet loss (or so I would have thought....).  None of
> the other network stuff shows any problems - although perhaps the fact
> that NTP uses UDP matters?  The internal stuff is polling at 64s
> intervals.

    Measure packet loss on your LAN, ideally between the same two machines.
Have one ping the other a hundred times, once a second. If you get a packet
loss of zero, then I'd be suspicious.

> Externally, through my router, cable modem, ISP, Internet etc. I hardly
> ever see reaches other than 377, and I would have thought the likelihood
> of packet loss to be far greater externally than internally.  Mind you
> external stuff is on 1024s polling.

> There's something here which seems counter-intuitive.

    Not always. It's easier to burst to the full available bandwidth on a
LAN than over a WAN.

    DS





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