T 3.27 Improper time synchronisation

Novell Netware 4.x allows several servers to interact within a network. To ensure smooth operation of network services, for example, for the creation of date and time stamps of files, review and auditing, and to guarantee time restrictions for login procedures, it is very important for all servers to indicate the same time of day. Changes to a directory tree also carry a time stamp in Novell Netware Version 4; which determines the processing sequence when the NDS is updated. For this reason, it is important to maintain identical times for all Netware 4 servers in a network.

Potential threats:

• If the internal hardware clock of a computer is not checked and, if necessary, adjusted prior to an installation of a Netware 4 server on that computer, it might not be possible for the new server to match itself with the remaining Netware 4 network, thus giving rise to the danger of the NDS malfunctioning.

• If the time source fails within a network which uses the single-reference procedure for time synchronisation, a replacement time is no longer available. This allows uncontrolled changes to file access rights and object access rights.

• NDS modifications whose time stamps lie far ahead in the future due to an incorrect system time are only executed on the actual attainment of these future deadlines. This might result in errors and problems which are hard or impossible to comprehend, due to the large time span between the issue and execution of the modifications.

• If, after the installation of the server, a radio clock is connected without prior deactivation of the automatic switch between summer and winter time, this will result in an additional adjustment by one hour