 Using SO many will help illustrate how NTP behaves. On Nexus switches with multiple VDCs, only the default VDC may have NTP configured. ntp server 132.163.4.102 ntp server 193.67.79.202 ntp server 152.1.58.124 ntp server 128.118.46.3 ntp server 129.6.15.29 ntp server 64.236.96.53 ntp server 208.184.49.9 Once you've configured the NTP servers, you should begin receiving accurate time signals (assuming you can reach them). To see the status of the NTP servers in IOS, use the command show ntp associa tions. In this chapter, I'll use the IP-PBX system I built in Chapter 30. This is a 2811 router running IOS version 15.0(1)M4: R1-PBX#sho ntp associations address ref clock reach delay of fset ~127.127.1.1 LOCL. 0.000 0.000 437.71 ~128.118.46.3 INIT. 0.000 0.000 15937. ~208.184.49.9 INIT. 0.000 0.000 15937. +~129.6.15.29 ACTS. 23.087 -4.829 939.32 *~64.236.96.53 ACTS. 18.705 -4.804 438.60 +^193.67.79.202 109.59 -5.209 439.79 ~132.163.4.102 ACTS. 118.13 15.596 938.89 ~192.168.1.250 64.236.96.53 2.802 -2.104 439.79 Configuring NTP ~152.1.58.124 INIT. 0.000 0.000 15937. * sys.peer, # selected, + candidate, - outlyer, X falseticker, ~ configured A lot of information is presented, but you only need to know what some of it means. The address is, obviously, the server you configured. To the left of the address are one or more symbols indicating the status of the server. The key for these symbols appears in the last line of the output; Table 38-1 provides more detailed explanations. The line beginning with an asterisk indicates the NTP server with which the router has synced its time. Notice how some of the entries have a stratum of 16 with a delay and offset of 0.000? These are dead NTP servers. You'll likely find many dead NTP servers if you look for them online. In fact, I took this list from the first edition of this book. Back in 2007, all of these IP addresses were live NTP servers. Make sure you check your configurations every year or SO to make sure your configured NTP servers are still active. Table 38-1. NTP associat