NTP synchronization

Question

Hi Guyz,

Please I need some help to get time synchronization from NTP servers on my F5 from NTP servers.
I have two F5 LTM running version 10.2.4 working in production as redundancy, one of them getting time from NTP server as well and other one failed.

Also there is new IPs for NTP server I have added them but getting failed on both F5, port 123 is opened for both F5.

Standby F5 name is (riyadh-f5b)(its IP:10.6.140.240) failed on old and new IPs, Active F5 name (riyadh-f5b)(its IP:10.6.140.241) successfully getting time from old NTP servers but also failed on new IPs.

Old IPs: 10.1.0.1 &amp; 10.1.0.1
New IPs: 10.1.9.11 &amp; 10.1.9.12

I will attached some info from both F5 and if there is more information required please let me know.

Standby F5a:

[root@riyadh-f5a:/S1-green-P:Standby] config  ntpq -p

remote           refid      st t when poll reach   delay   offset  jitter

10.1.0.1        .INIT.          16 u    - 1024    0    0.000    0.000   0.000
 10.1.0.2        .INIT.          16 u    - 1024    0    0.000    0.000   0.000
 10.1.9.11       .INIT.          16 u    - 1024    0    0.000    0.000   0.000
 10.1.9.12       .INIT.          16 u    - 1024    0    0.000    0.000   0.000
 slot1           .INIT.          16 u    - 1024    0    0.000    0.000   0.000
 slot2           .INIT.          16 u    - 1024    0    0.000    0.000   0.000
 slot3           .INIT.          16 u    - 1024    0    0.000    0.000   0.000
 slot4           .INIT.          16 u    - 1024    0    0.000    0.000   0.000
[root@riyadh-f5a:/S1-green-P:Standby] config  ntpdate
30 Jun 15:39:09 ntpdate[30699]: no servers can be used, exiting
[root@riyadh-f5a:/S1-green-P:Standby] config  ntpstat 
unsynchronised
  time server re-starting
   polling server every 64 s
[root@riyadh-f5a:/S1-green-P:Standby] config  ntpdate
30 Jun 15:53:23 ntpdate[1060]: no servers can be used, exiting
[root@riyadh-f5a:/S1-green-P:Standby] config  ntptrace 
localhost.localdomain: stratum 16, offset 0.000000, synch distance 1.434780
[root@riyadh-f5a:/S1-green-P:Standby] config  cat ntp.conf

THIS IS AN AUTO-GENERATED FILE -- DO NOT EDIT!!!

Use the bigpipe shell utility to make changes to the system configuration.

For more information, see bigpipe ntp help.

Permit time synchronization with our time source, but do not

permit the source to query or modify the service on this system.

restrict default kod nomodify notrap nopeer noquery 
restrict -6 default kod nomodify notrap nopeer noquery

Permit all access over the loopback interface.  This could

be tightened as well, but to do so would effect some of

the administrative functions.

restrict 127.0.0.1 
restrict -6 ::1

Allow queries from the TMM and SCCP.

restrict 127.1.1.2 nomodify notrap
restrict 127.2.0.1 nomodify notrap

--- GENERAL CONFIGURATION ---

Undisciplined Local Clock. This is a fake driver intended for backup

and when no outside source of synchronized time is available. The

default stratum is usually 3, but in this case we elect to use stratum

0. Since the server line does not have the prefer keyword, this driver

is never used for synchronization, unless no other other

synchronization source is available. In case the local host is

controlled by some external source, such as an external oscillator or

another protocol, the prefer keyword would cause the local host to

disregard all other synchronization sources, unless the kernel

modifications are in use and declare an unsynchronized condition.

server 10.1.0.1 iburst
server 10.1.0.2 iburst
server 10.1.9.11 iburst
server 10.1.9.12 iburst

peer 127.3.0.1
peer 127.3.0.2
peer 127.3.0.3
peer 127.3.0.4

Drift file.  Put this in a directory which the daemon can write to.

No symbolic links allowed, either, since the daemon updates the file

by creating a temporary in the same directory and then rename()'ing

it to the file.

driftfile /var/lib/ntp/drift
broadcastdelay  0.008

Keys file.

keys        /etc/ntp/keys

Active F5b:

[root@riyadh-f5b:/S1-green-P:Active] config  ntpq -np

remote           refid      st t when poll reach   delay   offset  jitter

+10.1.0.1        10.64.0.4        4 u  199 1024  377    1.821   -6.901   1.293
*10.1.0.2        10.64.0.4        4 u  293 1024  377    1.849   -4.921   1.882
 10.1.9.11       .INIT.          16 u    - 1024    0    0.000    0.000   0.000
 10.1.9.12       .INIT.          16 u    - 1024    0    0.000    0.000   0.000
 127.3.0.1       .INIT.          16 u    - 1024    0    0.000    0.000   0.000
 127.3.0.2       .INIT.          16 u    - 1024    0    0.000    0.000   0.000
 127.3.0.3       .INIT.          16 u    - 1024    0    0.000    0.000   0.000
 127.3.0.4       .INIT.          16 u    - 1024    0    0.000    0.000   0.000
[root@riyadh-f5b:/S1-green-P:Active] config  ntpdate
30 Jun 16:20:48 ntpdate[10040]: no servers can be used, exiting
[root@riyadh-f5b:/S1-green-P:Active] config  ntpstat 
synchronised to NTP server (10.1.0.2) at stratum 5 
   time correct to within 92 ms
   polling server every 1024 s
[root@riyadh-f5b:/S1-green-P:Active] config  ntptrace 
localhost.localdomain: stratum 5, offset 0.005461, synch distance 0.100876
10.1.0.2: stratum 4, offset 0.000676, synch distance 0.279300
10.64.0.4: timed out, nothing received
***Request timed out
[root@riyadh-f5b:/S1-green-P:Active] config  cat ntp.conf

THIS IS AN AUTO-GENERATED FILE -- DO NOT EDIT!!!

Use the bigpipe shell utility to make changes to the system configuration.

For more information, see bigpipe ntp help.

Permit time synchronization with our time source, but do not

permit the source to query or modify the service on this system.

restrict default kod nomodify notrap nopeer noquery 
restrict -6 default kod nomodify notrap nopeer noquery

Permit all access over the loopback interface.  This could

be tightened as well, but to do so would effect some of

the administrative functions.

restrict 127.0.0.1 
restrict -6 ::1

Allow queries from the TMM and SCCP.

restrict 127.1.1.2 nomodify notrap
restrict 127.2.0.1 nomodify notrap

--- GENERAL CONFIGURATION ---

Undisciplined Local Clock. This is a fake driver intended for backup

and when no outside source of synchronized time is available. The

default stratum is usually 3, but in this case we elect to use stratum

0. Since the server line does not have the prefer keyword, this driver

is never used for synchronization, unless no other other

synchronization source is available. In case the local host is

controlled by some external source, such as an external oscillator or

another protocol, the prefer keyword would cause the local host to

disregard all other synchronization sources, unless the kernel

modifications are in use and declare an unsynchronized condition.

server 10.1.0.1 iburst
server 10.1.0.2 iburst
server 10.1.9.11 iburst
server 10.1.9.12 iburst

peer 127.3.0.1
peer 127.3.0.2
peer 127.3.0.3
peer 127.3.0.4

Drift file.  Put this in a directory which the daemon can write to.

No symbolic links allowed, either, since the daemon updates the file

by creating a temporary in the same directory and then rename()'ing

it to the file.

driftfile /var/lib/ntp/drift
broadcastdelay  0.008

Keys file.

keys        /etc/ntp/keys

amolari · Answer

tcpdump with filter on ntp shows anything?&nbsp;
Have you checked your routing + firewall (if any) inbetween?&nbsp;
Just to mention...NTP won't take management interface by default but follow the routing table. If you want to "force" it through management interface, you have to add management-routes. I've seen such case many times.&nbsp;

omnix_tims_4122 · Answer

Hi amolari,&nbsp;
Great thanks brother, the issue was on management-routes which was not added for old and new IP in Standby F5.
now both are working fine.&nbsp;

shar_169852 · Answer

Hi&nbsp;
I got this to work by adding specific routes even though I had a default management-route. Try this:&nbsp;
tmsh create /sys management-route MyNTPserver network x.x.x.x/255.255.255.255 gateway y.y.y.y 
tmsh save /sys config
bigstart restart ntpd&nbsp;
Also, F5 documentation states:&nbsp;
"When the BIG-IP system starts, the ntpd process starts before the system loads the TMM network configuration, and the ntpd process attempts to use the management network to reach the NTP server. However, the attempt fails because the NTP server is on the TMM network."&nbsp;
(Reference: https://support.f5.com/kb/en-us/solutions/public/7000/000/sol7017.html)&nbsp;
Regards,
Sharmeelan&nbsp;

shar_169852 · Answer

*adjustment for spacing

tmsh create /sys management-route MyNTPserver network x.x.x.x/255.255.255.255 gateway y.y.y.y

tmsh save /sys config

bigstart restart ntpd

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NTP synchronization

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