Cisco ASA 5506-X Configuration Guide

9-12
Cisco ASA Series Firewall CLI Configuration Guide
Chapter 9 Network Address Translation (NAT)
Dynamic NAT
Dynamic NAT
The following topics explain dynamic NAT and how to configure it.
• About Dynamic NAT, page 9-12
• Configure Dynamic Network Object NAT, page 9-14
• Configure Dynamic Twice NAT, page 9-16
About Dynamic NAT
Dynamic NAT translates a group of real addresses to a pool of mapped addresses that are routable on the
destination network. The mapped pool typically includes fewer addresses than the real group. When a
host you want to translate accesses the destination network, the ASA assigns the host an IP address from
the mapped pool. The translation is created only when the real host initiates the connection. The
translation is in place only for the duration of the connection, and a given user does not keep the same
IP address after the translation times out. Users on the destination network, therefore, cannot initiate a
reliable connection to a host that uses dynamic NAT, even if the connection is allowed by an access rule.
Note For the duration of the translation, a remote host can initiate a connection to the translated host if an
access rule allows it. Because the address is unpredictable, a connection to the host is unlikely.
Nevertheless, in this case you can rely on the security of the access rule.
The following figure shows a typical dynamic NAT scenario. Only real hosts can create a NAT session,
and responding traffic is allowed back.
Figure 9-2 Dynamic NAT
10.1.1.1 209.165.201.1
Inside Outside
10.1.1.2 209.165.201.2
130032
Security
Appliance

Cisco ASA 5506-X Specifications

General

Model	ASA 5506-X
Firewall Throughput	750 Mbps
Maximum Firewall Connections	50, 000
Maximum VPN Peers	50
Integrated Ports	8 x 1 GE
Stateful Inspection Throughput	750 Mbps
Weight	4.4 lb (2 kg)
Firewall Throughput (Multiprotocol)	750 Mbps
Firewall Throughput (Application Visibility and Control AVC)	250 Mbps
Concurrent Sessions	50, 000
New Connections per Second	10, 000
IPsec VPN Throughput	100 Mbps
Interfaces	8 x 1 GE
Memory	4 GB
Flash Memory	8 GB
Form Factor	Desktop
VPN Throughput	100 Mbps
Maximum Concurrent Sessions	50, 000
New Sessions per Second	10, 000
Operating Temperature	32 to 104°F (0 to 40°C)
Storage Temperature	-13 to 158°F (-25 to 70°C)
Power Supply	External
Humidity	10% to 90% non-condensing