For putting out compiler fires.
As a practical matter, every computer architecture and operating system version seems to be different than any other. The device drivers may be different, the input/output system may be idiosyncratic and the libraries may have different semantics. It is not possible in a software distribution such as this one to support every individual sysdtem with a common set of binaries, even with the same system but different versions. Therefore, it is necessary to configure each system individually for each system and version, both at compile time and at run time. In almost all cases, these procedures are completely automatic and all the newbie user need do is type "make" and the autoconfigure system does the rest. There are some exceptions, as noted below.
Some programs included in this distribution use cryptographic algorithms to verify server authenticity and credentials. As required by the International Trade in Arms Regulations (ITAR), now called the Defense Trade Regulations (DTR), certain cryptographic products and media, including the Data Encryption Standard (DES), cannot be exported without per-instance license. For this reason, the DES encryption routine has been removed from the the current version, even though it is used only to compute a message digest. Current DTR regulations allow export of the the MD5 message digest routine, which is in fact the preferred algorithm, and this is included in the current version.
The NTP authentication routines conform to the interface used by RSA Laboratories in the rsaref20.zip package, which was formerly downloadable from ftp.rsa.com or via the web at www.rsa.com, but this may no longer be the case. Outside the US and Canada, the functionally identical rsaeuro.zip package is available from J.S.A. Kapp and other sources. The recommended way to integrate the routines in either package with the NTP build procedures is to uncompress and extract the rsaref20 files in a top level directory with that name. Then install a link to that directory from rsaref2 in the top level directory of the distribution. These steps must be completed before the configuration process described below.
The first thing to do is uncompress the distribution and extract the source tree. Use the ./configure command to perform an automatic configuration procedure. This command inspects the hardware and software environment and tests for the presence of system header files and the contents of these files to determine if certain features are present. When one or more of these features are present, the code is compiled to use them; if not, no special code is compiled. However, even if the code is compiled to use these features, the code does a special test at run time to see if one or more are actually present and avoids using them if not present. In such cases a warning message is sent to the system log, but the daemon should still work properly.
The default build normally includes the debugging code, which can be useful in diagnosing problems found in initial test, and all reference clock drivers known to work with each machine and operating system. Unless memory space is at a premium, this is a sensible strategy and saves lots of messy fiddling. If you need to delete either the debugging code or one or more or all reference clock drivers to save space, see the Configuration Options page.
If your site supports multiple architectures and uses NFS to share files, you can use a single source tree to compile executables for all architectures. While running on a target architecture machine and with the distribution base directory active, create a subdirectory using a command like mkdir A.`config.guess`, which will create an architecture-specific directory with name peculiar to the architecture and operating system. Then change to this directory and configure with the ../configure command. The remaining steps are the same whether building in the base directory or in the subdirectory.
Use the make command to compile all source modules, construct the libraries and link the distribution. Expect few or no warnings using cc and a moderate level of warnings using gcc. Note: On some Unix platforms the use of gcc can result in quite a few complaints about system header files and type inconsistencies, especially about pointer variables. This is usually the case when the system header files are not up to ANSI standards or gcc-isms, when gcc is not installed properly, or when operating system updates and patches are applied and gcc is not reinstalled. While the autoconfigure process is quite thorough, the Unix programming cultures of the various workstation makers still remain idiosyncratic.
If the precision time kernel modifications are present, the following program is installed:
If the public key authentication functions are present, the following program is installed:
In some systems that include the capability to edit kernel variables, the following program is installed:
You are now ready to configure the daemon and start it. You will need to create a NTP configuration file ntp.conf and possibly a cryptographic key file ntp.keys. Newbies should see the Quick Start page for orientation. Seasoned veterans can start with the ntpd - Network Time Protocol (NTP) daemon page and move on to the specific configuration option pages from there. A tutorial on NTP subnet design and configuration options is in the Notes on Configuring NTP and Setting up a NTP Subnet page.
If you have problems peculiar to the particular hardware and software environment (e.g. operating system-specific issues), browse the Hints and Kinks page. For other problems a tutorial on debugging technique is in the NTP Debugging Technique page. As always, the first line of general assistance is the NTP web site www.ntp.org and the FAQ resident there. Requests for assistance of a general nature and of interest to other timekeepers should be sent to the NTP newsgroup. Bug reports of a specific nature should be sent to <email@example.com>. Bug reports of a specific nature on features implemented by the programmer corps mentioned in the Copyright page should be sent directly to the implementor listed in that page, with copy to firstname.lastname@example.org.
Please include the version of the source distribution (e.g., ntp-4.0.70a) in your bug report, as well as billboards from the relevant utility programs and debug trace, if available. Please include the output of config.guess in your bug report. It will look something like:
Additional make commands