Page 398 - StudyBook.pdf

382 Chapter 6 • Infrastructure Security: Devices and Media

Packet Exchange/Sequenced Packet Exchange (IPX/SPX) or Network Basic
Input/Output System (NetBIOS).

EXAM WARNING
Knowing that specific protocols can be filtered through a RAS is very
important. This feature allows you to implement an additional layer of
security by keeping unauthorized protocols from being used on your
network. The Security+ exam expects you to have knowledge of this
security feature and to understand how it can help protect your net-
work. Blocking unnecessary traffic of this type functions to both reduce
your network bandwidth utilization, and prevent potential security
breaches using the unnecessary protocols.

When securing a RAS server, it is critical to use the best authentication
method possible for the environment. Implementing callback verification is also a
good idea. For example, if remote users always call from home, then callback verifi-
cation would work well and add another layer of security. However, if dealing with
a mobile sales force calling in from anywhere, callback verification as a security
mechanism is severely limited.
If an intruder detects dial-in numbers either through war dialing or some other
means, they will try everything possible to access the network through the RAS
server. Using strong password security for user accounts is critical to making it
more difficult for intruders to access the network. It is also a good idea to use user
IDs for the user’s RAS account that differ from their e-mail or standard LAN
access IDs.This makes it more difficult for intruders to access an internal network
should they manage to get through the RAS security, as they would still need to
determine the user’s normal LAN ID and password to access any network
resources.
Overall, RAS is an important service to provide when remote access is needed
via dial-up; however, it presents several security vulnerabilities that must be
addressed. Proper implementation of this service allows administrators to provide
for the remote access needs of their users while keeping their network as secure as
possible. Following is a list of industry best practices for keeping a RAS implemen-
tation secure:

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