[CentOS] ntp queries not being answered

[Nicolas Sahlqvist]

Ok, so it was indeed the firewall, thanks for letting me know! :)

(CCing the centos list in order to close the subject there too)


- Nicolas


On Nov 20, 2007 3:23 PM, Engineer, Gaurav <gaurav.engineer at lmco.com> wrote:
> This worked like a charm.  Thanks for all the help!
>
>
> -----Original Message-----
> From: Nicolas Sahlqvist [mailto:nicco77 at gmail.com]
> Sent: Tuesday, November 20, 2007 8:36 AM
> To: Engineer, Gaurav
> Subject: Re: [CentOS] ntp queries not being answered
>
> Hi Gaurav,
>
> You can check the output of "iptables -L -n" or use "setup" and check
> out what "Security Level" is set to under "Firewall configuration". In
> case it's enabled, you can disable it or add "Other ports" under
> "Customize".
>
>
> - Nicolas
>
>
> On Nov 20, 2007 2:20 PM, Engineer, Gaurav <gaurav.engineer at lmco.com>
> wrote:
> > Thanks for the reply Nicolas.
> >
> > I was thinking it was something dealing with security that might be
> > the problem.  Unfortunately, I am totally new to Centos and linux.  We
>
> > have another team that is responsible for loading processors with the
> OS.
> >
> > So nothing was done besides the initial base loading of the SW and
> > configuring the IP address.
> >
> > Can you please tell me how to deactivate the firewall (iptables) on
> > the linux box?  How to activate the ntp port?
> >
> >
> > -----Original Message-----
> > From: centos-bounces at centos.org [mailto:centos-bounces at centos.org] On
> > Behalf Of Nicolas Sahlqvist
> > Sent: Tuesday, November 20, 2007 8:14 AM
> > To: CentOS mailing list
> > Subject: Re: [CentOS] ntp queries not being answered
> >
> > On Nov 20, 2007 2:05 PM, Engineer, Gaurav <gaurav.engineer at lmco.com>
> > wrote:
> > >
> > >
> > >
> > > Hello All,
> > >
> > >
> > >
> > > My name is Gaurav, and I am tasked with configuring a linux box with
> > NTP.
> > >
> > > I am having a problem that I hope you can help me with.
> > >
> > > We have installed CentOS V5 on 1 processor down in the lab.  The
> > > rest
> > of the
> > > processors on the network are AIX boxes versions 3.2.5 and 5.2.  I
> > worked
> > > through the entire initial NTP configuration; setup the
> > > /etc/ntp.conf
> > file
> > > to point to the server, etc.
> > >
> > > Now when I run the ntpdate -d <address of server> on the linux box I
> > get all
> > > the right information.
> > >
> > > Also, when I run the same command with the address for another
> > non-linux box
> > > (AIX): ntpdate -d <address of non-linux box> I get all the right
> > information
> > > again.
> > >
> > > The problem is that the linux box does not answer queries of the
> > command to
> > > it.
> > >
> > > So if I enter the following on the non-linux box:
> > >
> > > Ntpdate -d <address of linux box>... all the values for offset, etc.
> > are all
> > > zeroed out.  So the linux box is not passing any information back to
> > the
> > > querying processor, even though the command works the other way
> > (executed on
> > > the linux box querying the non-linux box).   Also, I don't see the
> > usual
> > > "transmit....recieve" pattern for the command.... just the
> > "transmit...transmit...".
> > >
> > > Are there any reasons that the box can query the server and other
> > boxes
> > > successfully, but not answer queries sent to it?
> > >
> > > And in an effort to troubleshoot, I have commented out everything in
> > the
> > > /etc/ntp.conf file except the server address to see if there was
> > something
> > > in that file causing the problems, but that didn't work either.
> > >
> > >
> > >
> > > Do you have any information on this that could help me?  Anything at
> > all
> > > would be appreciated.
> >
> > Hi Gaurav,
> >
> > Have you ensured that the firewall (iptables) are deactivated or got
> > the ntp port open for ntp queries from the AIX boxes?
> >
> >
> > - Nicolas
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> >
>