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Cisco ASA Series CLI Configuration Guide
Chapter 1 Configuring Twice NAT
Feature History for Twice NAT
NAT support for reverse DNS lookups
9.0(1)
NAT now supports translation of the DNS PTR record for
reverse DNS lookups when using IPv4 NAT, IPv6 NAT, and
NAT64 with DNS inspection enabled for the NAT rule.
Per-session PAT
9.0(1)
The per-session PAT feature improves the scalability of PAT
and, for clustering, allows each member unit to own PAT
connections; multi-session PAT connections have to be
forwarded to and owned by the master unit. At the end of a
per-session PAT session, the ASA sends a reset and
immediately removes the xlate. This reset causes the end
node to immediately release the connection, avoiding the
TIME_WAIT state. Multi-session PAT, on the other hand,
uses the PAT timeout, by default 30 seconds. For
“hit-and-run” traffic, such as HTTP or HTTPS, the
per-session feature can dramatically increase the
connection rate supported by one address. Without the
per-session feature, the maximum connection rate for one
address for an IP protocol is approximately 2000 per
second. With the per-session feature, the connection rate for
one address for an IP protocol is 65535/
average-lifetime
.
By default, all TCP traffic and UDP DNS traffic use a
per-session PAT xlate. For traffic that requires multi-session
PAT, such as H.323, SIP, or Skinny, you can disable
per-session PAT by creating a per-session deny rule.
We introduced the following commands:
xlate per-session
,
show nat pool
.
Table 1-1
Feature History for Twice NAT (continued)
Feature Name
Platform
Releases
Feature Information
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: ......