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Cisco ASA 5500 Series Configuration Guide using the CLI
Chapter31 Configuring Twice NAT
Licensing Requirements for Twice NAT
Twice NAT also lets you use service objects for static NAT-with-port-translation; network object NAT
only accepts inline definition.
For detailed information about the differences between twice NAT and network object NAT, see the
“How NAT is Implemented” section on page29-16.
Twice NAT rules are added to section 1 of the NAT rules table, or if specified, section 3. For more
information about NAT ordering, see the “NAT Rule Order” section on page29-20.
Licensing Requirements for Twice NATPrerequisites for Twice NAT
For both the real and mapped addresses, configure network objects or network object groups (the
object network or object-group network command). Network object groups are particularly useful
for creating a mapped address pool with discontinuous IP address ranges or multiple hosts or
subnets. To create a network object or group, see the “Configuring Objects and Groups” section on
page 13-1.
For static NAT-with-port-translation, configure TCP or UDP service objects (the object service
command). To create a service object, see the “Configuring a Service Object” section on page 13-4.
For specific guidelines for objects and groups, see the configuration section for the NAT type you want
to configure. See also the “Guidelines and Limitations” section.
Guidelines and Limitations
This section includes the guidelines and limitations for this feature.
Context Mode Guidelines
Supported in single and multiple context mode.
Firewall Mode Guidelines
Supported in routed and transparent firewall mode.
In transparent mode, you must specify the real and mapped interfaces; you cannot use any.
In transparent mode, you cannot configure interface PAT, because the transparent mode interfaces
do not have IP addresses. You also cannot use the management IP address as a mapped address.
IPv6 Guidelines
Does not support IPv6.
Model License Requirement
All models Base License.