Objective
Configure Port Address Translation (PAT) to allow multiple internal devices to share a single public IP address.
Task 1 – Define Interfaces
Identify inside and outside interfaces.
R1(config)# interface gigabitEthernet 0/0 R1(config-if)# ip nat inside R1(config-if)# exit R1(config)# interface gigabitEthernet 0/1 R1(config-if)# ip nat outside
Task 2 – Create Access List
Define which internal addresses are allowed to be translated.
R1(config)# access-list 1 permit 192.168.1.0 0.0.0.255
Task 3 – Configure NAT Overload
Map the list to the outside interface using overload.
R1(config)# ip nat inside source list 1 interface gigabitEthernet 0/1 overload
Task 4 – Verification
Generate traffic from an inside host and check the translation table.
R1# show ip nat translations Pro Inside global Inside local Outside local Outside global icmp 203.0.113.1:1024 192.168.1.10:1 8.8.8.8:1 8.8.8.8:1