Cisco ASA 5505 Configuration Manual page 523

Configuring Network Object NAT
All NAT rules that are configured as a parameter of a network object are considered to be network object
NAT rules. Network object NAT is a quick and easy way to configure NAT for a network object, which
can be a single IP address, a range of addresses, or a subnet. After you configure the network object, you
can then identify the mapped address for that object.
This chapter describes how to configure network object NAT, and it includes the following sections:
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Note For detailed information about how NAT works, see
Information About Network Object NAT
When a packet enters the adaptive security appliance, both the source and destination IP addresses are
checked against the network object NAT rules. The source and destination address in the packet can be
translated by separate rules if separate matches are made. These rules are not tied to each other; different
combinations of rules can be used depending on the traffic.
Because the rules are never paired, you cannot specify that a source address should be translated to A
when going to destination X, but be translated to B when going to destination Y. Use twice NAT for that
kind of functionality (twice NAT lets you identify the source and destination address in a single rule).
For detailed information about the differences between twice NAT and network object NAT, see the
"How NAT is Implemented" section on page
Network object NAT rules are added to section 2 of the NAT rules table. For more information about
NAT ordering, see the
OL-20339-01
Information About Network Object NAT, page 27-1
Licensing Requirements for Network Object NAT, page 27-2
Prerequisites for Network Object NAT, page 27-2
Guidelines and Limitations, page 27-2
Configuring Network Object NAT, page 27-3
Configuration Examples for Network Object NAT, page 27-17
Feature History for Network Object NAT, page 27-37
"NAT Rule Order" section on page
C H A P T E R
Chapter 26, "Information About NAT."
26-15.
26-19.
Cisco ASA 5500 Series Configuration Guide using ASDM
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27-1