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Linux: A Network Solution for Your Office ContentsIndex Chapter 14: Time Services: The Need for Synchronization Previous ChapterNext Chapter Sections in this Chapter: The Need for Synchronization Summary UNIX, the Internet, and Timekeeping Manual Pages Installing and Using NTP Software Previous SectionNext Section Chapter 14 Time Services The built-in clocks of most personal computers are notoriously inaccurate. Even newer models run fast or slow by several seconds, sometimes whole minutes each day. Yet for quite some time now, I've been used to my computers always displaying the time, accurate to the second. Cool, you say, the author is a mad perfectionist; but what's the point? Is there a practical use, or need, for keeping your computers' clocks accurate? The Need for Synchronization Synchronizing Hosts Synchronizing to an External Service When all you have is a simple computer that you use to browse the Web occasionally, it is indeed irrelevant whether your computer's clock shows the proper time. However, when you have several computers interacting via a network, synchronization becomes important. When you save a file to a network file server, you want the file's time and date stamp to mean the same thing on both systems. Even more importantly, some cooperative software packages actually depend on the assumption that all participating computers have the same time. Synchronizing Hosts To solve this problem, you need to synchronize all the computers on the network to a single host. This can be accomplished in a variety of ways, depending on the operating systems in use and the software packages installed. It doesn't matter if the computers don't actually display an accurate time; what is important is that they always display the same time, and shared network services will operate properly. Synchronizing to an External Service Going one step further, it is also possible to synchronize your computers to an accurate external time source. For many years, software packages have been available that use your modem to connect to a well-known time service (for example, the time service of the U.S. Naval Observatory) to get the current time. Now it is also possible to do this via the Internet. The most comprehensive solution for this is provided by the Network Time Protocol (NTP). Linux: A Network Solution for Your Office ContentsIndex Chapter 14: Time Services: The Need for Synchronization Previous ChapterNext Chapter Sections in this Chapter: The Need for Synchronization Summary UNIX, the Internet, and Timekeeping Manual Pages Installing and Using NTP Software Previous SectionNext Section © Copyright Macmillan USA. All rights reserved. |