Asus SL1200 - Manual (Page 77)

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Chapter 9 - Configuring Firewall/NAT Settings
ASUS SL1200
9.1.4 Default ACL Rules
The router supports three types of default access rules:
• Inbound Access Rules: For controlling incoming access to
computers on your LAN.
• Outbound Access Rules: For controlling outbound access to
external networks for hosts on your LAN.
• Self Access Rules: For controlling access to the Internet Security
Router itself.
Default Inbound Access Rules
No default inbound access rule is configured. All traffic from external hosts
to the internal hosts is denied.
Default Outbound Access Rules
The default outbound access rule allows all the traffic originated from your
LAN to be forwarded to the external network using NAT.
It is not necessary to remove the default ACL rule from the
ACL rule table. It is better to create higher priority ACL rules
to override the default rule.
9.2 NAT Overview
Network Address Translation (NAT) allows the use of a single device, such
as the router, to act as an agent between the Internet (public network) and
a local (private) network. This means that a NAT IP address can represent
an entire group of computers to any entity outside a network. NAT is a
mechanism for conserving registered IP addresses in large networks
and simplifying IP addressing management tasks. The translation of IP
addresses enable NAT to conceal the true network address from privy
eyes and provide a degree of security to the local network.
The NAT modes supported are static NAT, dynamic NAT, NAPT, reverse
static NAT, and reverse NAPT.