17-31
Cisco Security Appliance Command Line Configuration Guide
OL-12172-03
Chapter 17 Configuring NAT
Bypassing NAT
Note
If you change the NAT configuration, and you do not want to wait for existing translations to time out
before the new NAT information is used, you can clear the translation table using the
clear xlate
command. However, clearing the translation table disconnects all current connections that use
translations.
To configure identity NAT, enter the following command:
hostname(config)#
nat
(
real_interface
)
0
real_ip
[
mask
[
dns
] [
outside
] [
norandomseq
]
[[
tcp
]
tcp_max_conns
[
emb_limit
]] [
udp
udp_max_conns
]
See the
“Configuring Dynamic NAT or PAT” section on page 17-23
for information about the options.
For example, to use identity NAT for the inside 10.1.1.0/24 network, enter the following command:
hostname(config)#
nat (inside) 0 10.1.1.0 255.255.255.0
Configuring Static Identity NAT
Static identity NAT translates the real IP address to the same IP address. The translation is always active,
and both “translated” and remote hosts can originate connections. Static identity NAT lets you use
regular NAT or policy NAT. Policy NAT lets you identify the real and destination addresses when
determining the real addresses to translate (see the
“Policy NAT” section on page 17-10
for more
information about policy NAT). For example, you can use policy static identity NAT for an inside address
when it accesses the outside interface and the destination is server A, but use a normal translation when
accessing the outside server B.
Figure 17-25
shows a typical static identity NAT scenario.
Figure 17-25
Static Identity NAT
Note
If you remove a
static
command, existing connections that use the translation are not affected. To remove
these connections, enter the
clear local-host
command.
You cannot clear static translations from the translation table with the
clear xlate
command; you must
remove the
static
command instead. Only dynamic translations created by the
nat
and
global
commands
can be removed with the
clear xlate
command.
To configure static identity NAT, enter one of the following commands:
•
To configure policy static identity NAT, enter the following command:
209.165.201.1
209.165.201.1
Inside
Outside
209.165.201.2
209.165.201.2
130036
Security
Appliance
Содержание 500 Series
Страница 38: ...Contents xxxviii Cisco Security Appliance Command Line Configuration Guide OL 12172 03 ...
Страница 45: ...P A R T 1 Getting Started and General Information ...
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Страница 277: ...P A R T 2 Configuring the Firewall ...
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Страница 354: ...17 38 Cisco Security Appliance Command Line Configuration Guide OL 12172 03 Chapter 17 Configuring NAT NAT Examples ...
Страница 561: ...P A R T 3 Configuring VPN ...
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Страница 891: ...P A R T 4 System Administration ...
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Страница 975: ...P A R T 5 Reference ...
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