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Cisco ASA Series CLI Configuration Guide
Chapter 1 Information About NAT
NAT Types
shows a typical many-to-few static NAT scenario.
Figure 1-5
Many-to-Few Static NAT
Instead of using a static rule this way, we suggest that you create a one-to-one rule for the traffic that
needs bidirectional initiation, and then create a dynamic rule for the rest of your addresses.
Dynamic NAT
This section describes dynamic NAT and includes the following topics:
•
Information About Dynamic NAT, page 1-7
•
Dynamic NAT Disadvantages and Advantages, page 1-8
Information 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.
shows a typical dynamic NAT scenario. Only real hosts can create a NAT session, and
responding traffic is allowed back.
Figure 1-6
Dynamic NAT
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Summary of Contents for 5505 - ASA Firewall Edition Bundle
Page 28: ...Glossary GL 24 Cisco ASA Series CLI Configuration Guide ...
Page 61: ...P A R T 1 Getting Started with the ASA ...
Page 62: ......
Page 219: ...P A R T 2 Configuring High Availability and Scalability ...
Page 220: ......
Page 403: ...P A R T 2 Configuring Interfaces ...
Page 404: ......
Page 499: ...P A R T 2 Configuring Basic Settings ...
Page 500: ......
Page 533: ...P A R T 2 Configuring Objects and Access Lists ...
Page 534: ......
Page 601: ...P A R T 2 Configuring IP Routing ...
Page 602: ......
Page 745: ...P A R T 2 Configuring Network Address Translation ...
Page 746: ......
Page 845: ...P A R T 2 Configuring AAA Servers and the Local Database ...
Page 846: ......
Page 981: ...P A R T 2 Configuring Access Control ...
Page 982: ......
Page 1061: ...P A R T 2 Configuring Service Policies Using the Modular Policy Framework ...
Page 1062: ......
Page 1093: ...P A R T 2 Configuring Application Inspection ...
Page 1094: ......
Page 1191: ...P A R T 2 Configuring Unified Communications ...
Page 1192: ......
Page 1333: ...P A R T 2 Configuring Connection Settings and QoS ...
Page 1334: ......
Page 1379: ...P A R T 2 Configuring Advanced Network Protection ...
Page 1380: ......
Page 1475: ...P A R T 2 Configuring Modules ...
Page 1476: ......
Page 1549: ...P A R T 2 Configuring VPN ...
Page 1550: ......
Page 1965: ...P A R T 2 Configuring Logging SNMP and Smart Call Home ...
Page 1966: ......
Page 2059: ...P A R T 2 System Administration ...
Page 2060: ......
Page 2098: ...1 8 Cisco ASA Series CLI Configuration Guide Chapter 1 Troubleshooting Viewing the Coredump ...
Page 2099: ...P A R T 2 Reference ...
Page 2100: ......