ntpd fails to synchronize on FreeBSD 6.3-STABLE

[Clifton Royston]

On Thu, Feb 28, 2008 at 09:02:20PM +0700, Pongthep Kulkrisada wrote:
> > You're not getting responses back from __any__ of those NTP servers.  If
> > you have a firewall *in front* of your BSD box (meaning a separate box,
> > not ipfw/ipfilter/pf on the same BSD box!), then this is likely the
> > cause of the problem.
> The question is that two weeks ago, with same machine, same gateway, same NAT and same firewall config, when I was on FreeBSD 6.2-RELEASE and behind NAT, I could sync with ALL IPv6 servers (IPv4 is not functioning there) I said that in my first post.
> I'm pretty sure that if I went back to 6.2 even behind NAT, I could get sync with IPv6. Long writing since my first post I shall summarize my events here for better understanding, and sorry for redundancy.
> 1. FreeBSD 5.4-RELEASE(dial up) - can sync all servers
> 2. FreeBSD 6.2-RELEASE(dial up) - can sync all servers
> 3. FreeBSD 6.2-RELEASE(NAT)     - can sync IPv6 servers

  What the first 3 items in your list suggest, totally independent of
any questions involving 6.3 vs. 6.2, is that you don't have a NAT/LAN
configuration which works correctly with NTP on IPv4.

  Do any other UDP services work with NAT on IPv4, under either 6.2,
6.3, or 5.4?

  If you want to confirm this is the problem, try running 6.3-STABLE on
the same dialup connection that worked for 5.4 and 6.2.  My prediction
is that NTP will work via your dialup connection. 

  If that is case, your problem is that your NAT implementation is
broken or incomplete, or your NAT configuration also incorporates a
firewall blocking NTP.  (Note also that if you connect through dial-up,
naturally you're not going through any firewall present on the LAN, so
a firewall could well be the problem.)

  -- Clifton

-- 
    Clifton Royston  --  cliftonr at iandicomputing.com / cliftonr at lava.net
       President  - I and I Computing * http://www.iandicomputing.com/
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