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of general interest. The value sync_ntp in the first line tells you that this router has<br />

synchronized its time with an NTP server. If the output shows sync_alarm or sync_<br />

unspec, it means that the router is not synched. This could mean that it was more<br />

than 128 seconds off and never synched, but assuming that it was synched at least<br />

once since it was manufactured, it more likely means that none of its NTP servers are<br />

themselves synched or they are unreachable. Having multiple stratum 1 servers minimizes<br />

the chances of this latter case happening. If the router’s time has drifted more<br />

than 128 seconds from the time on the NTP server, manually reset the time on the<br />

router with the set date ntp command.<br />

Another field of interest is stratum. This output shows that the NTP server is a stratum<br />

2 time source, so it is one hop from a stratum 1 server. The refid field lists the<br />

stratum 1 server. If the value in this field shows 0.0.0.0, it provides another indication<br />

that the router’s clock is not synchronized with the NTP server.<br />

190 | Chapter 6: NTP<br />

This is the Title of the Book, eMatter Edition<br />

Copyright © 2008 O’Reilly & Associates, Inc. All rights reserved.

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