Nat Examples - Cisco Catalyst 6500 Series Configuration Manual

NAT Examples

Figure 9-19
Figure 9-20 NAT Exemption
209.165.201.1
209.165.201.2
If you change the NAT configuration, and you do not want to wait for existing translations to time out
Note
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.
To configure NAT exemption, enter the following command:
FWSM/contexta(config)# FWSM/contexta(config)# nat ( local_interface ) 0 access-list acl_name
[outside] [norandomseq] [[tcp] tcp_max_conns [ emb_limit ]] [udp udp_max_conns ]
Create the ACL using the access-list command (see the
section on page
specify the local and destination ports in the ACL; NAT exemption does not consider the ports.
See the
For example, to exempt an inside network when accessing any destination address, enter the following
command:
FWSM/contexta(config)# access-list EXEMPT permit ip 10.1.2.0 255.255.255.0 any
FWSM/contexta(config)# nat (inside) 0 access-list EXEMPT
To exempt an inside address when accessing two different destination addresses, enter the following
commands:
FWSM/contexta(config)# access-list NET1 permit ip 10.1.2.0 255.255.255.0 209.165.201.0
255.255.255.224
FWSM/contexta(config)# access-list NET1 permit ip 10.1.2.0 255.255.255.0 209.165.200.224
255.255.255.224
FWSM/contexta(config)# nat (inside) 0 access-list NET1
NAT Examples
The following sections show typical scenarios that use NAT solutions:
•
•
Catalyst 6500 Series Switch and Cisco 7600 Series Router Firewall Services Module Configuration Guide
9-32
shows a typical NAT exemption scenario.
FWSM
Inside Outside
10-13). This ACL should include only permit access control entries (ACEs). Do not
"Configuring NAT or PAT" section on page 9-23
Overlapping Networks, page 9-33
Redirecting Ports, page 9-34
Chapter 9
209.165.201.1
209.165.201.2
"Adding an Extended Access Control List"
for information about the other options.
Configuring Network Address Translation
OL-6392-01