[ntp:questions] NTP over IPv6 with Teredo
Danny Mayer
mayer at ntp.isc.org
Mon Feb 18 02:59:58 UTC 2008
Ronan Flood wrote:
> At my workplace we're slipping in IPv6 on our NTP servers, and I've
> been watching the traffic and checking out the clients which pop up,
> to see if they hit any problems when unintentionally using IPv6
> instead of IPv4.
>
> Native-IPv6 and 6to4-tunnel clients seem OK, but I've found one client
> using a Teredo tunnel (RFC 4380), and it looks like that is something
> to be avoided:
>
> remote refid st t when poll reach delay offset jitter
> ---------------------------------------------------------------------
> +2001:630:1:101: .GPS. 1 u 621 1024 177 350.111 115.061 2.000
> -2001:630:1:102: .MSF. 1 u 617 1024 177 355.528 114.905 0.734
> -2001:630:1:103: .PPS. 1 u 631 1024 177 575.602 222.278 0.056
> +195.66.241.3 .PPS. 1 u 524 1024 377 22.724 -15.799 0.788
> *195.66.241.10 .IRIG. 1 u 753 1024 377 27.490 -15.864 0.775
> 127.127.1.0 .LOCL. 13 l 28 64 377 0.000 0.000 0.002
>
> Being a UK client, using a Teredo server on the west coast of the US
> probably doesn't help, but it could also be inherent latency in Teredo.
>
You might ask why they have configured their NTP server to go to the
west coast of the US in the first place, irrespective of Teredo since
network wise it a much longer distance than say some other location in
London.
All tunnels will have additional delays being Teredo, VPN or something else.
> "server -4" would be wise here :-/
>
Only if the really need to go distances like this.
Danny
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