Cisco Systems ASA 5555-X Network Router User Manual


 
5-23
Cisco ASA Series Firewall CLI Configuration Guide
Chapter 5 Configuring Twice NAT
Configuring Twice NAT
Step 3
nat [(real_ifc,mapped_ifc)]
[line |{after-object [line]}]
source static {nw_obj nw_obj | any any}
[destination static {mapped_obj |
interface [ipv6]} real_obj]
[service real_src_mapped_dest_svc_obj
mapped_src_real_dest_svc_obj]
[no-proxy-arp] [route-lookup] [inactive]
[description desc]
Example:
ciscoasa(config)# nat (inside,outside)
source static MyInsNet MyInsNet
destination static Server1 Server1
Configures identity 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 page 3-18 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—Specify a network object, group, or the
any keyword for both the real and mapped addresses.
Destination addresses (Optional):
Mapped—Specify a network object or group, or for static
interface NAT with port translation only, specify the
interface keyword (routed mode only).If you specify
ipv6, then the IPv6 address of the interface is used. 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. See the
“Static Interface NAT with Port Translation” section on
page 3-5 for more information.
Real—Specify a network object or group. For identity
NAT, simply use the same object or group for both the
real and mapped addresses.
Port—(Optional) Specify the service keyword along with the
real and mapped service objects. For source port translation,
the objects must specify the source service. The order of the
service objects in the command for source port translation is
service real_obj mapped_obj. For destination port
translation, the objects must specify the destination service.
The order of the service objects for destination port
translation is service mapped_obj real_obj. In the rare case
where you specify both the source and destination ports in the
object, the first service object contains the real source
port/mapped destination port; the second service object
contains the mapped source port/real destination port. For
identity port translation, simply use the same service object
for both the real and mapped ports (source and/or destination
ports, depending on your configuration).
Command Purpose