ntpio_process_ipv4: no ntp subblock

[peteralbino]

Has anyone encountered the error above? I keep getting the alerts and I see that one of my ntp status shows INIT. I tried removing that ntp (insane) from the router and alarms disappeared. I somehow can not establish ntp sync with it but my other routers are able to. I'm using Version 12.4(24)T, RELEASE SOFTWARE (fc1) on both my routers and the other one is able to sync with it,

[DAVID MYERS]

I have upgraded a Cisco 1841 router to version 12.4(24)T4 and encountered a similar problem. Previously the router was running 12.4(9)T4 and could sync via NTP with an NTP Server running on a Cisco 2921 router (15.1(2)T1). The 1841 sends NTP packets, but receives nothing back and logs the same condition (ntpio_process_ipv4: no ntp subblock). The two routers are connected via an MPLS WAN. The two devices are also reachable via DMVPN configured on internet services used for backup. If I route the ntp requests over the dynamic GRE tunnel ntp synchronises.

At another site I have a 2811 router also running 12.4(24)T4 which is able to synchronise with  a local NTP server running on a Cisco 1841 router running 12.4(9)T4 - but this is reachable via a LAN connection.

Maybe there is an issue with this version of IOS when ntp is operating over certain types of  WAN link. What WAN links do you have in your network?

[walter baziuk]

I have upgraded a Cisco 3845 router to version 12.4(24)T4 and encountered a similar problem

The NTP server is in its own subnet with a pt-pt connection betwen the rtr and the NTP server

I have a local NTP server with a GPS signal

sh ntp ass looks fine

yet i see these logs every few minutes

any one else know what this issue is or how to address it?

This is the log i get every 17 seconds
>>
030012: Jan 23 21:47:05.109 gmt: ntpio_process_ipv4: no ntp subblock.
030013: Jan 23 21:47:22.141 gmt: ntpio_process_ipv4: no ntp subblock.
030014: Jan 23 21:47:39.174 gmt: ntpio_process_ipv4: no ntp subblock.
030015: Jan 23 21:47:56.206 gmt: ntpio_process_ipv4: no ntp subblock.
030016: Jan 23 21:48:13.235 gmt: ntpio_process_ipv4: no ntp subblock.
030017: Jan 23 21:48:30.267 gmt: ntpio_process_ipv4: no ntp subblock.
030018: Jan 23 21:48:47.300 gmt: ntpio_process_ipv4: no ntp subblock.
030019: Jan 23 21:49:04.328 gmt: ntpio_process_ipv4: no ntp subblock.
030020: Jan 23 21:49:21.361 gmt: ntpio_process_ipv4: no ntp subblock.
030021: Jan 23 21:49:38.389 gmt: ntpio_process_ipv4: no ntp subblock.
030022: Jan 23 21:49:55.422 gmt: ntpio_process_ipv4: no ntp subblock.
030023: Jan 23 21:50:12.454 gmt: ntpio_process_ipv4: no ntp subblock.
>>

my pc's can't sync to the rtr via ntp, they all get sync error
My rtr can sync to the GPS NTP time source
sh ntp ass
  address         ref clock       st   when   poll reach  delay  offset   disp
*~x.x.x.x         .NTP.            1    740   1024   377  0.000  10.970 11.241
* sys.peer, # selected, + candidate, - outlyer, x falseticker, ~ configured

%lan 80 is a pt to pt between the ntp server and the rtr
scheduler allocate 20000 1000
ntp master 5
ntp update-calendar
ntp server prefer source GigabitEthernet0/0.80

does anyone know what the issue is?

[jaredkelsey]

I turned on this debugging:

NTP:
  NTP core messages debugging is on
  NTP events debugging is on
  NTP packets debugging is on (detailed)
  NTP reference clocks debugging is on (detailed)

And found this in the log:

Sep 18 12:44:48.693 EDT: NTP recv pkt on v4 socket, pak = 0x47CA51AC.
Sep 18 12:44:48.693 EDT: ntpio_process_ipv4: no ntp subblock.
Sep 18 12:45:52.699 EDT: NTP recv pkt on v4 socket, pak = 0x47CA704C.
Sep 18 12:45:52.699 EDT: ntpio_process_ipv4: no ntp subblock.
Sep 18 12:46:56.696 EDT: NTP recv pkt on v4 socket, pak = 0x485AE498.
Sep 18 12:46:56.696 EDT: ntpio_process_ipv4: no ntp subblock.

Each time I see the "no ntp subblock" error it is preceded by NTP receiving a packet. I have packet detail debugging turned on but no packet details are displayed. However, when I receive an update packet from one of my NTP peers I see those packet details.

How can I see more about those packets?

[jaredkelsey]

I rebooted my router and the errors went away. :-)