IT Baseline Protection Manual - The Information Warfare Site

Safeguard Catalogue - Communications Remarks
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- How quickly can a RAS connection be restored (by replacement of
equipment, restarting the system)?
- Which component failures require that the RAS system is shut down even
though technically RAS connections can still be established (e.g. failure of
logging, encryption of communications or of the authentication server)?
For remote users, an emergency call number should be available so that they
can notify the responsible persons promptly of any RAS problems. Moreover,
the RAS system should be permanently monitored at critical periods (e.g.
office hours, periods in which data is primarily exchanged by RAS).
Suitable procedures should be developed for individual damage scenarios in
the form of contingency documentation. All the data that is necessary to
resolve an emergency should be included in this documentation and presented
in such a way that deputising staff can also work with it. The contingency
documentation should also contain information on alternative connection
paths, e.g. alternative telecommunications providers or alternative
transmission media.
Depending on the availability requirements for the RAS system, it may be
necessary to hold replacement equipment in reserve so that faulty items can be
replaced immediately. To ensure that the RAS system can be started up again
after equipment replacement or a system crash, the contingency
documentation must contain a recovery plan. If necessary, it may even be
necessary for it to be possible to replace certain components while the system
is running. Such a hot swap must be supported by the components used.
Depending on the RAS system, the consistency of data being transmitted by
RAS during a system crash cannot be assured. After every failure the integrity
of this data should therefore be checked and a problem analysis should be
carried out in order to avoid repetitions as far as possible.
In certain situations it can be necessary to operate the RAS system with
limited functionality or performance. In this case a corresponding fallback
configuration must be activated (see also S 4.111 Secure configuration of the
RAS system). This enables the security of the RAS system (access security,
communication security) to be maintained even during restricted operation.
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IT-Baseline Protection Manual: Oktober 2000
Setting up emergency
call numbers
Create contingency
documentation
Prepare recovery plan
Check data integrity after
failures
Secure emergency
configuration