31-18
Cisco ASA 5500 Series Configuration Guide using the CLI
Chapter31 Configuring Twice NAT
Configuring Twice NAT
Step6 nat [(real_ifc,mapped_ifc)]
[line |{after-object [line]}]
source static real_ob
[mapped_obj |interface]
[destination static {mapped_obj |
interface} real_obj]
[service real_src_mapped_dest_svc_obj
mapped_src_real_dest_svc_obj] [dns]
[no-proxy-arp] [inactive]
[description desc]
Example:
hostname(config)# nat (inside,dmz) source
static MyInsNet MyInsNet_mapped
destination static Server1 Server1 service
REAL_SRC_SVC MAPPED_SRC_SVC
Configures static NAT. See the following guidelines:
Interfaces—(Required for transparent mode) Specify the real
and mapped interfaces. Be sure to include the parentheses in
your command. In routed mode, if you do not specify the real
and mapped interfaces, all interfaces are used; you can also
specify the keyword any for one or both of the interfaces.
Section and Line—(Optional) By default, the NAT rule is
added to the end of section 1 of the NAT table. See the “NAT
Rule Order” section on page29-20 for more information
about sections. If you want to add the rule into section 3
instead (after the network object NAT rules), then use the
after-auto keyword. You can insert a rule anywhere in the
applicable section using the line argument.
Source addresses:
Real—Specify a network object or group (see Step1).
Mapped—Specify a different network object or group
(see Step 2). For static interface NAT with port
translation only, you can specify the interface keyword
(routed mode only). If you specify interface, be sure to
also configure the service keyword (in this case, the
service objects should include only the source port). For
this option, you must configure a specific interface for
the mapped_ifc. See the “Static Interface NAT with Port
Translation” section on page29-5 for more information.
Destination addresses (Optional):
Mapped—Specify a network object or group, or for static
interface NAT with port translation only, specify the
interface keyword (see Step 4). If you specify interface,
be sure to also configure the service keyword (in this
case, the service objects should include only the
destination port). For this option, you must configure a
specific interface for the real_ifc.
Real—Specify a network object or group (see Step3).
For identity NAT, simply use the same object or group for
both the real and mapped addresses.
Command Purpose