D-Link DFL-80 User Manual page 131

Mapped IP
Both Mapped IP and Virtual Server use IP mapping mechanism to allow outside
users access internal servers through the firewall. They are different in following
ways:
!
Virtual Server has Load balance feature, and Mapped IP does not.
!
Virtual Server has a one-to-many mapping relationship to physical
servers and Mapped IP is mapped to physical servers in one-to-one fashion. A
virtual server can be mapped to only one service, such as SMTP, HTTP or FTP.
A Mapped IP can be mapped to all services provided by a physical server.
Policy
The DFL-80 decides whether a data packet can pass according to values of
the policies. A policy's parameters are source address, destination address,
service, permission, packets' history, statistics and flow alarms. Policies can
be divided into four categories based on the packets' source addresses.
!
Outgoing : Clients are located in internal networks and servers are in
!
Incoming : Clients are located in external networks and servers are in
!
To DMZ :
!
From DMZ : Clients are in DMZ and servers are in either internal or
Packet
Direction
Source
Network
Destination
network
external networks.
internal networks.
Client can be located in either internal or external networks
and servers are in DMZ.
external networks
Outgoing Incoming
Internal External
Mapped
IP
External
Virtual
Server
To DMZ From DMZ
External,
DMZ
internal
External,
DMZ
internal
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