interface ethernet 0
ip address 10.10.10.1 255.255.255.0
ip nat inside
!--- Defines Ethernet 0 with an IP address and as a NAT inside interface.
interface ethernet 1
ip address 10.10.20.1 255.255.255.0
ip nat inside
!--- Defines Ethernet 1 with an IP address and as a NAT inside interface.
interface serial 0
ip address 172.16.10.64 255.255.255.0
ip nat outside
!--- Defines serial 0 with an IP address and as a NAT outside interface.
ip nat pool no-overload 172.16.10.1 172.16.10.63 prefix 24
!
!--- Defines a NAT pool named no-overload with a range of addresses
!--- 172.16.10.1 - 172.16.10.63.
ip nat inside source list 7 pool no-overload
!
!
!--- Indicates that any packets received on the inside interface that
!--- are permitted by access-list 7 has
!--- the source address translated to an address out of the
!--- NAT pool "no-overload".
access-list 7 permit 10.10.10.0 0.0.0.31
access-list 7 permit 10.10.20.0 0.0.0.31
!--- Access-list 7 permits packets with source addresses ranging from
!--- 10.10.10.0 through 10.10.10.31 and 10.10.20.0 through 10.10.20.31.