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Catalyst 6500 Series Switch and Cisco 7600 Series Router Firewall Services Module Configuration Guide using ASDM
OL-20748-01
Chapter 16 Configuring NAT
Using Static PAT
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.
Static translations from the translation table can be removed using the
clear xlate
command; the
translation table will be cleared and all current translations are deleted.
To configure static PAT, enter one of the following commands.
•
For policy static PAT, enter the following command:
hostname(config)#
static (
real_interface
,
mapped_interface
)
{
tcp
|
udp
}
mapped_ip
mapped_port
access-list
acl_name
[
dns
]
[[
tcp
]
tcp_max_conns
[
emb_limit
]]
[
udp
udp_max_conns
] [
norandomseq
]
Identify the real addresses and destination/source addresses using an extended access list. Create the
extended access list using the
access-list extended
command. (See the
“Adding an Extended Access
List” section on page 13-6
.) The protocol in the access list must match the protocol you set in this
command. For example, if you specify
tcp
in the
static
command, then you must specify
tcp
in the
access list. Specify the port using the
eq
operator.
The first address in the access list is the real address; the second address is either the source or
destination address, depending on where the traffic originates. For example, to translate the real
address 10.1.1.1/Telnet to the mapped address 192.168.1.1/Telnet when 10.1.1.1 sends traffic to the
209.165.200.224 network, the
access-list
and
static
commands are:
hostname(config)#
access-list TEST extended tcp host 10.1.1.1 209.165.200.224
255.255.255.224 eq telnet
hostname(config)#
static (inside,outside) tcp 192.168.1.1 telnet access-list TEST
In this case, the second address is the destination address. However, the same configuration is used
for hosts to originate a connection to the mapped address. For example, when a host on the
209.165.200.224/27 network initiates a Telnet connection to 192.168.1.1, then the second address
in the access list is the source address.
This access list should include only
permit
ACEs. Policy NAT and static NAT consider the
inactive
or
time-range
keywords and stop working when an ACE is inactive. See the
“Policy NAT” section
on page 16-10
for more information.
If you specify a network for translation (for example, 10.1.1.0 255.255.255.0), then the FWSM
translates the .0 and .255 addresses. If you want to prevent access to these addresses, be sure to
configure an access list to deny access.
See the
“Configuring Dynamic NAT or PAT” section on page 16-26
for information about the other
options.
•
To configure regular static PAT, enter the following command:
hostname(config)#
static (
real_interface
,
mapped_interface
)
{
tcp
|
udp
}
mapped_ip
mapped_port real_ip real_port
[
netmask
mask
] [
dns
] [[
tcp
]
tcp_max_conns
[
emb_limit
]]
[
udp
udp_max_conns
] [
norandomseq
]
See the
“Configuring Dynamic NAT or PAT” section on page 16-26
for information about the
options.
For example, for Telnet traffic initiated from hosts on the 10.1.3.0 network to the FWSM outside
interface (10.1.2.14), you can redirect the traffic to the inside host at 10.1.1.15 by entering the following
commands:
hostname(config)#
access-list TELNET permit tcp host 10.1.1.15 10.1.3.0 255.255.255.0 eq
telnet
Содержание 6500 - Catalyst Series 10 Gigabit EN Interface Module Expansion
Страница 35: ...P A R T 1 Getting Started and General Information ...
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Страница 297: ...P A R T 2 Configuring the Security Policy ...
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Страница 521: ...P A R T 3 System Administration ...
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Страница 613: ...P A R T 4 Reference ...
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