NAT Router
ip nat pool test 172.16.131.2 172.16.131.10 netmask 255.255.255.0
ip nat inside source list 7 pool test
ip nat inside source static 10.10.10.1 172.16.131.1
interface e 0
ip address 10.10.10.254 255.255.255.0
ip nat inside
interface s 0
ip address 172.16.131.254 255.255.255.0
ip nat outside
access-list 7 deny host 10.10.10.1
access-list 7 permit 10.10.10.0 0.0.0.255