fips191_4
FIPS PUB 191
1.3 Overview of Document
Section 1 - Introduction - This section discusses the properties of a LAN, and the security
concerns that result from those properties.
Section 2 - Threats, Vulnerabilities, Security Services & Mechanisms - This section describes
threats, related vulnerabilities and the possible security services and mechanisms that could be
used to protect the LAN from these threats.
Section 3 - Risk Management - This section describes the risk management process and how it
can be used to plan and implement appropriate LAN security.
1.4 LAN Definition
The Institute of Electrical and Electronic Engineers (IEEE) has defined a LAN as "a datacomm
system allowing a number of independent devices to communicate directly with each other,
within a moderately sized geographic area over a physical communications channel of moderate
rates" [MART89]. Typically, a LAN is owned, operated, and managed locally rather than by a
common carrier. A LAN usually, through a common network operating system, connects servers,
workstations, printers, and mass storage devices, enabling users to share the resources and
functionality provided by a LAN.
According to [BARK89] the types of applications provided by a LAN include distributed file
storing, remote computing, and messaging.
1.4.1 Distributed File Storing
Distributed file storing provides users transparent access to part of the mass storage of a remote
server. Distributed file storing provides capabilities such as a remote filing and remote printing.
Remote filing allows users to access, retrieve, and store files. Generally remote filing is provided
by allowing a user to attach to part of a remote mass storage device (a file server) as though it
were connected directly. This virtual disk is then used as though it were a disk drive local to
the workstation. Remote printing allows users to print to any printer attached to any component
on the LAN. Remote printing addresses two user needs: ongoing processing while printing, and
shared use of expensive printers. LAN print servers can accept files immediately, allowing users
to continue work on their local workstations, instead of waiting for the print job to be completed.
Many users utilizing the same printer can justify the cost of high quality, fast printers.
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