interface Loopback0 ip address 10.0.1.1 255.255.255.252 ip nat outside !--- Creates a virtual interface called Loopback 0 and assigns an !--- IP address of 10.0.1.1 to it. Defines interface Loopback 0 as !--- NAT outside. ! ! interface Ethernet0 ip address 192.168.1.2 255.255.255.0 secondary ip address 10.0.0.2 255.255.255.0 ip Nat inside !--- Assigns a PRimary IP address of 10.0.0.2 and a secondary IP !--- address of 192.168.1.2 to Ethernet 0. Defines interface Ethernet 0 !--- as NAT inside. The 192.168.1.2 address will be used to communicate !--- through the CM to the CMTS and the Internet. The 10.0.0.2 address !--- will be used to communicate with the local hosts.
ip policy route-map Nat-loop !--- Assigns route-map "Nat-loop" to Ethernet 0 for policy routing. ! ip Nat pool external 192.168.2.2 192.168.2.3 prefix-length 29 ip Nat inside source list 10 pool external overload ip Nat inside source static 10.0.0.12 192.168.2.1 !--- NAT is defined: packets matching access-list 10 will be !--- translated to an address from the pool called "external". !--- A static NAT translation is defined for 10.0.0.12 to be !--- translated to 192.168.2.1 (this is for host 2 which needs !--- to be accessed from the Internet).
ip classless ! ! ip route 0.0.0.0 0.0.0.0 192.168.1.1 ip route 192.168.2.0 255.255.255.0 Ethernet0 !--- Static default route set as 192.168.1.1, also a static !--- route for network 192.168.2.0/24 directly attached to !--- Ethernet 0 ! ! access-list 10 permit 10.0.0.0 0.0.0.255 !--- Access-list 10 defined for use by NAT statement above.
access-list 102 permit ip any 192.168.2.0 0.0.0.255 access-list 102 permit ip 10.0.0.0 0.0.0.255 any !--- Access-list 102 defined and used by route-map "Nat-loop" !--- which is used for policy routing. ! Access-list 177 permit icmp any any !--- Access-list 177 used for debug. ! route-map Nat-loop permit 10 match ip address 102 set ip next-hop 10.0.1.2 !--- Creates route-map "Nat-loop" used for policy routing. !--- Route map states that any packets matching access-list 102 will !--- have the next hop set to 10.0.1.2 and be routed "out" the !--- loopback interface. All other packets will be routed normally. ! end NAT-router#
