ntp interlude...

of course you know this already...

manually set your offset for the time zone you are in...

core1#sh run | b clock                                                         
clock timezone est -5     

pick a server out there to set your time...

core1#sh run | b ntp                                                           
ntp clock-period 36028813                                                      
ntp server 96.47.67.105 

the clock period will be derived for you...

core1#sh ntp assoc                                                             
                                                                               
      address         ref clock     st  when  poll reach  delay  offset    disp
*~96.47.67.105     .ACTS.            1    29    64  377    19.2    0.97     2.9
 * master (synced), # master (unsynced), + selected, - candidate, ~ configured 

core1#sh clock                                                                 
06:51:36.698 est Thu Jan 3 2013                                                
core1#sh ntp status                                                            
Clock is synchronized, stratum 2, reference is 96.47.67.105                    
nominal freq is 119.2092 Hz, actual freq is 119.2092 Hz, precision is 2**17    
reference time is D48FEF26.3C49206B (06:51:02.235 est Thu Jan 3 2013)          
clock offset is 0.9651 msec, root delay is 19.20 msec                          
root dispersion is 3.91 msec, peer dispersion is 2.94 msec 

it can take a few minutes to get synced...

now you want to distribute the time in your switched network... because i said you do...

on the other switches, set the timezone offset and peer to the master, which in this case is core1...

core2(config)#ntp peer 10.1.10.1

core2#sh ntp assoc                                                             
                                                                               
      address         ref clock     st  when  poll reach  delay  offset    disp
*~10.1.10.1        96.47.67.105      2     0    64  377     2.4   -0.13     0.4
  192.168.1.23     96.47.67.105      2  3123    64    0     0.0    0.00  16000.
 * master (synced), # master (unsynced), + selected, - candidate, ~ configured 
core2#sh clock                                                                 
07:08:02.023 est Thu Jan 3 2013   

192.168.1.23 is the routed port the time comes in on...        

note that i changed the master as i progressed further down the switched network, as in hierarchically...

als2#sh ntp assoc                                                              
                                                                               
      address         ref clock     st  when  poll reach  delay  offset    disp
*~10.1.10.12       10.1.10.1         3    37    64  377     3.9    0.29     0.3
 * master (synced), # master (unsynced), + selected, - candidate, ~ configured 


isn't that exciting?

now go look up ntp on the doccd...

 http://www.cisco.com/en/US/docs/ios-xml/ios/bsm/configuration/12-4t/bsm-time-calendar-set.html

it's in the basic section...

have you abused your doccd yet today?

isn't it funny that all the subjects you study in ciscopress books can be found right there?

for God's sake don't tell anybody...

show ntp love...

network time protocol

your phone system will need to have it's time sync'd and it would be a good idea for your network in general... the good folks at the free organizations request that you limit one device in your network and IOS readily obliges...

first find a supporting site...  there is this thing called google...


Name IP Address Location
nist1-ny.ustiming.org 64.90.182.55 New York City, NY
nist1-nj.ustiming.org 96.47.67.105 Bridgewater, NJ

r2620_01(config)#ntp server 64.90.182.55

r2620_01(config)#do sh ntp assoc

      address         ref clock     st  when  poll reach  delay  offset    disp

*~64.90.182.55     .ACTS.            1    54    64  377    39.5    1.83     4.4

 ~127.127.7.1      127.127.7.1       3    11    64  377     0.0    0.00     0.0

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

notice the master...

then add the other devices...

sw2950_02(config)#ntp peer 192.168.1.50

sw2950_02(config)#do sh ntp assoc

      address         ref clock     st  when  poll reach  delay  offset    disp

 ~192.168.1.50     64.90.182.55     16  1937    64    0     5.1    0.18  16000.

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

sw2950_02(config)#

notice the peer...  the world on time...