Each machine should be set up with the following:
The current, stable versions of the operating system and all the supporting software, such as Apache, database manager, scripting language, etc. It is obviously essential that all machines on the site should be running the same versions of all these products.
Currently working TCP/IP layer with all up-to-date patches.
The correct time: since elements of the HTTP protocol use the time of
day — it is worth using Unix’s
xntpd (http://www.eecis.udel.edu/~ntp/),
Win32’s ntpdate
(http://www.eecis.udel.edu/~ntp/ntp_spool/html/ntpdate.html),
or Tardis (http://www.kaska.demon.co.uk)
to make sure your machines keep accurate time.