Re: Firewalled NTP on Redhat - ntpdate works, but ntpq doesn't

From: Stephen Carville <stephen@xxxxxxxxxxxxxx>
Date: Fri, 18 May 2007 13:01:17 -0700

Young, Mike wrote:

Hello,

I'm seeing an odd NTP problem on a couple of Redhat servers here.
Basically the NTP client is on a firewalled DMZ, away from the NTP server.
NTP updates via ntpq work fine on the local NTP server subnet, but it
isn't working for hosts on the firewalled DMZ. We've checked ports on the
firewall, and 123/UDP is open. In addition, we see packets incrementing
when we use the "iostat" command in ntpdc, and don't see any dropped or
ignored packets in iostat either.

Any ideas?

Does the firewall allow port 123 in _both_ directions? NTP requires unrestricted access to 123/udp for _both_ source and destination.

Thanks,
Mike.

--
Stephen Carville <stephen@xxxxxxxxxxxxxx>
Systems Engineer
Land America
1.626.667.1450 X326

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