ZyXEL Communications VMG1312-B Series, Руководство пользователя

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VMG1312-B Series User’s Guide
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C
H A P T E R
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Firewall
15.1 Overview
This chapt er shows you how t o enable and configure t he Device’s securit y set t ings. Use t he firewall
t o prot ect your Device and net work from at t acks by hackers on t he I nt ernet and cont rol access t o
it . By default t he firewall:
• allows t raffic t hat originat es from your LAN com put ers t o go t o all ot her net works.
• blocks t raffic t hat originat es on ot her net works from going t o t he LAN.
The following figure illust rat es t he default firewall act ion. User A can init iat e an I M ( I nst ant
Messaging) session from t he LAN t o t he WAN ( 1) . Ret urn t raffic for t his session is also allowed ( 2) .
However ot her t raffic init iat ed from t he WAN is blocked ( 3 and 4) .
Figure 99 Default Firewall Act ion
15.1.1 What You Can Do in this Chapter
• Use t he Ge n e r a l screen t o configure t he securit y level of t he firewall on t he Device ( Sect ion 15.2
on page 219 ) .
• Use t he Se r vice screen t o add or rem ove predefined I nt ernet services and configure firewall
rules ( Sect ion 15.3 on page 219 ) .
• Use t he Acce ss Con t r ol screen t o view and configure incom ing/ out going filt ering rules ( Sect ion
15.4 on page 221 ) .
• Use t he D oS screen t o act ivat e prot ect ion against Denial of Service ( DoS) at t acks ( . Sect ion 15.5
on page 224 ) .
WAN
LAN
3
4
1
2
A