Lab 6. IP Services - NTP

Let's make ip p2p and IGP as follow:

R1#

interface Loopback0

 ip address 1.1.1.1 255.255.255.255

 ip ospf 1 area 0

!

interface FastEthernet0/0

 ip address 12.12.12.1 255.255.255.0

 ip ospf 1 area 0

 no shut

R2#

interface Loopback0

 ip address 2.2.2.2 255.255.255.255

 ip ospf 1 area 0

!

interface FastEthernet0/0

 ip address 12.12.12.2 255.255.255.0

 ip ospf 1 area 0

 no shut

Let’s create NTP server in R1. Then R1 & R2 have ntp authentication

R1#

R1#clock set 11:41:00 15 december 2011   ---- > in exec mode

R1(config)#clock timezone jakarta 7

R1(config)#ntp master 2

R1(config)#ntp authentication-key 1 md5 cisco

R2#

R2(config-if)#ntp server 1.1.1.1

R2(config)#ntp authentication-key 1 md5 cisco

R2(config)#ntp authenticate

R2(config)#ntp trusted-key 1

R2(config)#ntp server 1.1.1.1 key 1

Verify ntp & clock

R1#show clock

11:44:37.511 jakarta Thu Dec 15 2011

R1#show ntp status

Clock is synchronized, stratum 2, reference is 127.127.7.1

nominal freq is 250.0000 Hz, actual freq is 250.0000 Hz, precision is 2**18

reference time is D293F98E.65638BB2 (11:43:58.396 jakarta Thu Dec 15 2011)

clock offset is 0.0000 msec, root delay is 0.00 msec

root dispersion is 0.02 msec, peer dispersion is 0.02 msec

R1#sh ntp associations

      address         ref clock     st  when  poll reach  delay  offset    disp

*~127.127.7.1      .LOCL.            1    45    64  377     0.0    0.00     0.0

 * master (synced), # master (unsynced), + selected, - candidate, ~ configured

R2(config)#do sh clock

.04:44:47.834 UTC Thu Dec 15 2011

R2(config)#do sh ntp stat

Clock is unsynchronized, stratum 16, no reference clock

nominal freq is 250.0000 Hz, actual freq is 250.0000 Hz, precision is 2**18

reference time is C029479E.E7672A48 (00:19:42.903 UTC Fri Mar 1 2002)

clock offset is 308982290666.1083 msec, root delay is 91.71 msec

root dispersion is 19965208.94 msec, peer dispersion is 16000.00 msec

Just wait! Check again!

R2(config)#do sh ntp stat

Clock is synchronized, stratum 3, reference is 1.1.1.1

nominal freq is 250.0000 Hz, actual freq is 250.0000 Hz, precision is 2**18

reference time is D2945B98.1C940849 (11:42:16.111 UTC Thu Dec 15 2011)

clock offset is -13.7526 msec, root delay is 27.68 msec

root dispersion is 25.10 msec, peer dispersion is 11.31 msec

R2(config)#do sh ntp associ 

      address         ref clock     st  when  poll reach  delay  offset    disp

 ~1.1.1.1          127.127.7.1       2    20    64    0    91.7  308982  16000.

 * master (synced), # master (unsynced), + selected, - candidate, ~ configured

Oupsss… the clock is not the same!!! Make sure the time zone is the same!

R2(config)#clock timezone jakarta 7

Dec 15 04:46:03.776: %SYS-6-CLOCKUPDATE: System clock has been updated from 04:46:03 UTC Thu Dec 15 2011 to 11:46:03 jakarta Thu Dec 15 2011, configured from console by console.

R2(config)#do sh clock

11:46:09.589 jakarta Thu Dec 15 2011