[NTLUG:Discuss] NTP Problems

[Michael Barnes]

On Thu, Jun 12, 2008 at 8:31 AM, terry <trryhend at gmail.com> wrote:
> Try:
> utpdate -u ip.of.time.server
>
> -u       Specifies the use of an unprivileged port to send the packets
> from. Useful when you are behind a firewall that blocks incoming
> traffic to privileged ports, and you want to synchronize with hosts
> beyond the firewall. A firewall is a system or machine that controls
> the access from outside networks to a private network.
>
>
> On Wed, Jun 4, 2008 at 10:43 AM, Michael Barnes <barnmichael at gmail.com> wrote:
>> I have two ntp servers running, one on SUSE and one on Centos4.
>> Clients cannot get time from the Centos4 server.
>>
>> ntp.conf on SUSE (rdserv)(working)
>>
>> restrict default nomodify
>> restrict 127.0.0.1
>> restrict 10.33.0.0  mask 255.255.0.0   nomodify notrap
>> server 10.33.8.22 iburst
>> server 0.pool.ntp.org
>> server 1.pool.ntp.org
>> server 2.pool.ntp.org
>> driftfile /var/lib/ntp/drift/ntp.drift # path for drift file
>> logfile /var/log/ntp            # alternate log file
>>
>>
>> ntp.conf on Centos4 (bridge)(not working)
>>
>> restrict default nomodify
>> restrict 127.0.0.1
>> restrict 10.33.0.0  mask 255.255.0.0   nomodify notrap
>> server 10.113.35.150 iburst
>> logfile /var/log/ntpq
>> driftfile /var/lib/ntp/drift
>>
>> When I try to get time from another client, I get
>>
>> srn-td-desk:~ # ntpdate bridge
>>  4 Jun 10:28:57 ntpdate[3013]: no server suitable for synchronization found
>> srn-td-desk:~ # ntpdate rdserv
>>  4 Jun 10:29:04 ntpdate[3014]: adjust time server 10.33.8.16 offset 0.000948 sec
>>
>>
>> Running netstat shows it is listening:
>> bridge netstat (not working)
>> udp        0      0 10.33.8.22:123                  0.0.0.0:*
>> udp        0      0 10.113.35.100:123             0.0.0.0:*
>> udp        0      0 127.0.0.1:123                    0.0.0.0:*
>> udp        0      0 0.0.0.0:123                        0.0.0.0:*
>> udp        0      0 fe80::20e:cff:fedc:f479:123   :::*
>> udp        0      0 fe80::211:11ff:fe6f:123         :::*
>> udp        0      0 ::1:123                               :::*
>> udp        0      0 :::123                                 :::*
>>
>> rdserv netstat (working)
>> udp        0      0 10.33.8.16:123          0.0.0.0:*
>> udp        0      0 127.0.0.1:123            0.0.0.0:*
>> udp        0      0 0.0.0.0:123                0.0.0.0:*
>> udp        0      0 :::123                         :::*
>>
>>
>> Any ideas on why I cannot put time from the Centos machine?
>>
>> Thanks,
>> Michael
>>



Turned out it was a problem with iptables on the server.  Once I got
the commands in the right order, it works fine.

Thanks for all your help and comments.

Michael