IT Baseline Protection Manual - The Information Warfare Site

Networked Systems
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6.7 Heterogeneous Networks
Description
A local network is composed of wiring (i.e. cables and
connecting elements, which are passive network components)
as well as active network coupling components. Generally,
various types of cable and active network components can be
integrated into a LAN. Active network components require a
separate power supply. Such components include repeaters,
bridges, switches, routers, gateways etc. Passive network
components do not require a separate power supply. Such components include cables, distributor
cabinets, patch fields and plug connectors.
Cabling is discussed in detail in Chapter 4.2, while Chapters 5 and 6 deal with application-related
periphery. Consequently, this module focuses on the active network components, the topology
underlying them, their configuration, criteria for choosing suitable components, the selection of
communication protocols and the related network management.
Only LAN technologies, e.g. Ethernet, Token Ring and FDDI network protocols and the related
network components such as bridges, switches and routers are considered here. These technologies
can also be used in MANs. However, integration into WANs is not discussed here; this information is
provided in Chapter 7.3 "Firewalls".
If a LAN is to be protected adequately from the perspective of IT baseline protection, a reference to
this chapter alone is not sufficient. In addition to the active network components and network
management software, a treatment of the physical wiring and of the server systems present in the
network is also required. For this reason, it is absolutely necessary to refer to the above-mentioned
chapters as well.
This chapter provides guidelines on how to analyse a heterogeneous network and use this analysis as a
basis for realising and operating such a network from the perspective of IT security. Consequently,
this chapter is intended for organisational departments responsible for operating networks and in
possession of the corresponding technical know-how.
Threat Scenario
The following typical threats are assumed as regards IT baseline protection of a heterogeneous
network:
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IT-Baseline Protection Manual: Otober 2000