Cisco NTP clients not working with windows 2012 R2 server

[arumugasamy]

Team,

Thanks for your first level support to the vendor who reduce to open the TAC cases because of your best support and help

Customer need to configure ntp for 130 Cisco 3560 switches using windows 2012 R3 server as NTP server.

R4#sh ntp associations detail
192.168.100.151 configured, insane, invalid, stratum 1
ref ID .LOCL., time DA63EEE6.5CE12472 (07:51:50.362 gmt Tue Feb 9 2016)
our mode client, peer mode server, our poll intvl 64, peer poll intvl 64
root delay 0.00 msec, root disp 1039.10, reach 377, sync dist 1065.71
delay 3.28 msec, offset 39276107.3224 msec, dispersion 16.94
precision 2**6, version 3
org time DA63F6D5.8AF59F53 (08:25:41.542 gmt Tue Feb 9 2016)
rec time DA635D69.721A6EE7 (21:31:05.445 gmt Mon Feb 8 2016)
xmt time DA635D69.7133E991 (21:31:05.442 gmt Mon Feb 8 2016)
filtdelay = 3.51 3.28 4.08 10.96 15.52 4.24 4.23 5.13
filtoffset = 3927609 3927610 3927609 3927610 3927611 3927611 3927610 3927611
filterror = 15.62 16.58 17.54 18.52 19.49 20.47 21.43 22.40
minpoll = 6, maxpoll = 10

!

How can we solve this NTP to SNTP issues between Cisco (NTP) and server (SNTP)

Thx 

[Rolf Fischer]

Hi,

R4#sh ntp associations detail
192.168.100.151 configured, insane, invalid, stratum 1
ref ID .LOCL., time DA63EEE6.5CE12472 (07:51:50.362 gmt Tue Feb 9 2016)
our mode client, peer mode server, our poll intvl 64, peer poll intvl 64
root delay 0.00 msec, root disp 1039.10, reach 377, sync dist 1065.71

could be Bug CSCed13703:

"An IOS system may be unable to synchronize to an NTP server
despite being able to transmit to and receive packets
from the server. This may be seen with a Windows system
running the w32time service.

'show ntp associations detail" will show that the server is
flagged as "insane, invalid". The "root dispersion" value
will be seen as being in excess of 1000 ms, which will cause
the IOS NTP implementation to reject the association.

Workaround: instead of running the w32time service on the
Windows system, use NTP 4.x - see
http://www.eecis.udel.edu/~mills/ntp/html/hints/winnt.html"

HTH
Rolf

[Tagir Temirgaliyev]

make google search. for windows 2012 configuration is different than w2003

[Richard Burts]

I am not sure about the 3560 but most Cisco IOS devices have support for SNTP as well as for NTP.

HTH

Rick

[Tagir Temirgaliyev]

SNTP typically provides time within 100 milliseconds of the accurate time.

do your customer really need more accurate time? I dont think even in complicated process control systems they need