User Guide

McAfee Firewall
136 McAfee Office
Some network communications are needed to maintain network-based
services. These are managed through u ser defined r ules under the SYSTEM
button feature o f McAfee Firewall. The default SYSTEM setting s feature
provides protection from hostile threats.
Inaddition,duringtheinstallationprocess,itwillprompty ouw ithsomebasic
questions to set up McAfee Firewall to do specific tasks, according to your
needs (e.g. allo w sharing of file s or not).
About Winsock 2
McAfe e Firewall uses an API (App lication Pr ogramming Interface) that is no t
supportedby version s of Winsockprior to v2.0. McAfee Firewall checks for
the presence of W insock 2 during the installation procedure and will inform
youif thesystemdoesnothaveit. Ifyou havethe latestbrowser(e.g.,Internet
Explorer 5), this component is already built-in a nd you will not r eceive this
prompt. Ot herwise, you can get a free upgra de and is av ailable from
http://www.microsoft.com as well as other Web sites.
Configuring McAfee Firewall
Th e configura tion of McAfee Firew all is divided into two parts—application
and system. Upon installation, a b ase set of rules for system services such as
ICMP, DH CPa nd ARP is inst alled (these are considered defa ult settings). The
applications part i s personalized. Whenever you run a new program that
attemptstoco mmun icateover t he Internet,McAfeeFirewallwillpromptyou
whether you trusttheprogram or not.
For example, using the Netscape Web browser, enter a Web address or the
UniformResourceLocatorinthelocationbarandthenpressENTER.Netscape
willattempttoconnecttothatURLovertheInternet.Thefirsttimeyoudothis ,
McAfee Firewall prompts if you "trust" Netscape. If you say "Yes", McAfee
Firewall notes N et scape is a llow ed and when ever you use Netscape in the
future, Mc Afee Firewall w ill allow Netscape traffic.
Behind the scenes, McAfee Firewall creates a rule allowing Netscape to
communic ate to thespecific URL you have indicated a nd then delet esther ule
once all traffic is received or once you exit Netscape. Additionally, when
trojan sonyoursystemtrytocommunicateoutfromyourPC,M cAfeeFirewall
will also prompt you whether you trust them or not, and the decision to stop
trojan s is easy and instantaneous.