Cisco Systems Different Translation Depending on the Destination Address and Port (Dynamic PAT)

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Cisco ASA Series Firewall CLI Configuration Guide
Chapter5 Configuring Twice NAT
Configuration Examples for Twice NAT
Different Translation Depending on the Destination Address and Port (Dynamic
PAT)
Figure 5-2 shows the use of source and destination ports. The host on the 10.1.2.0/24 network accesses
a single host for both web services and Telnet services. When the host accesses the server for Telnet
services, the real address is translated to 209.165.202.129:port. When the host accesses the same server
for web services, the real address is translated to 209.165.202.130:port.
Figure5-2 Twice NAT with Different Destination Ports
Step1 Add a network object for the inside network:
ciscoasa(config)# object network myInsideNetwork
ciscoasa(config-network-object)# subnet 10.1.2.0 255.255.255.0
Step2 Add a network object for the Telnet/Web server:
ciscoasa(config)# object network TelnetWebServer
ciscoasa(config-network-object)# host 209.165.201.11
Step3 Add a network object for the PAT address when using Telnet:
ciscoasa(config)# object network PATaddress1
ciscoasa(config-network-object)# host 209.165.202.129
Step4 Add a service object for Telnet:
ciscoasa(config)# object service TelnetObj
ciscoasa(config-network-object)# service tcp destination eq telnet
Web and Telnet server:
209.165.201.11
Internet
Inside
Translation
209.165.202.12910.1.2.27:80
10.1.2.27
10.1.2.0/24
Translation
209.165.202.13010.1.2.27:23
Web Packet
Dest. Address:
209.165.201.11:80
Telnet Packet
Dest. Address:
209.165.201.11:23
130040