Hi All,
need help with nat setup, so my setup is as follows (just on packet tracer), i have 4 routers which can be seen below , R1, R2, R3 and the Gateway 1.1.1.1 which is supposed to be my isp. so will refer to it as ISP.
If i ignore R2, and concentrate on R1 setup.
R1 has two interfaces, one connects to 192.168.1.0/23 network with ip 192.168.1.1 which goes to the switch and then has another interface which is on a
10.10.10.0/30 subnet with IP 10.10.10.6
R3 also has two interfaces, again 10.10.10.0/30 with ip 10.10.10.5 , communication between R1 and R3 is fine
R3 other interface is on a serial connection with network 1.1.1.0/30 and ip 1.1.1.2 , which connects to the ISP router
ISP router only has one interface subnet 1.1.1.0/30 , ip 1.1.1.1
R3 and the ISP can ping between each other, but R1 cannot ping the ISP
I added a route to the isp for the 10.10.10.0/24 network to go to 1.1.1.2 and then pings worked fine.
But in real world this would not happen, i want to simulate NAT so that when i ping from R1 , it hits its default gateway which is R3 , then R3 NATs the traffic out on its 1.1.1.2 address, then NATs it back on the incoming to the 10.10.10.0/24 network?
I've tried various things and read a fair few articles but still not getting anywhere
R3 and ISP are connected both on serial2/0
R1 and R3 are conencted via R3 fastEthernet1/0 and R1 Gigabitethernet0/2
R1 does have the route 0.0.0.0 0.0.0.0 10.10.10.5 in its config and R3 has same except routes to 1.1.1.1
can someone please explain the commands i would need to put into all the routers to get NAT working correctly?
, 
Configs are below incase anyone wants a flick through, and thank you for taking the time to read and reply.
R1 config
Current configuration : 858 bytes
!
version 15.1
no service timestamps log datetime msec
no service timestamps debug datetime msec
service password-encryption
!
hostname Router
!
!
!
enable secret 5 $1$mERr$hx5rVt7rPNoS4wqbXKX7m0
!
!
!
!
ip cef
no ipv6 cef
!
!
!
!
license udi pid CISCO2911/K9 sn FTX1524R5SC
!
!
!
!
!
!
!
!
!
!
!
spanning-tree mode pvst
!
!
!
!
!
!
interface GigabitEthernet0/0
ip address 192.168.1.1 255.255.255.0
duplex auto
speed auto
!
interface GigabitEthernet0/1
no ip address
duplex auto
speed auto
shutdown
!
interface GigabitEthernet0/2
ip address 10.10.10.6 255.255.255.252
duplex auto
speed auto
!
interface Vlan1
no ip address
shutdown
!
ip classless
ip route 0.0.0.0 0.0.0.0 10.10.10.5
!
ip flow-export version 9
!
!
!
!
!
!
!
line con 0
exec-timeout 0 0
password 7 0822455D0A16
logging synchronous
!
line aux 0
!
line vty 0 4
login
!
!
!
end
R3 config
Current configuration : 957 bytes
!
version 12.2
no service timestamps log datetime msec
no service timestamps debug datetime msec
service password-encryption
!
hostname Router
!
!
!
enable secret 5 $1$mERr$hx5rVt7rPNoS4wqbXKX7m0
!
!
!
!
ip cef
no ipv6 cef
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
interface FastEthernet0/0
ip address 10.10.10.1 255.255.255.252
ip nat outside
duplex auto
speed auto
!
interface FastEthernet1/0
ip address 10.10.10.5 255.255.255.252
ip nat outside
duplex auto
speed auto
!
interface Serial2/0
ip address 1.1.1.2 255.255.255.252
ip nat inside
clock rate 2000000
!
interface Serial3/0
no ip address
clock rate 2000000
shutdown
!
interface FastEthernet4/0
no ip address
shutdown
!
interface FastEthernet5/0
no ip address
shutdown
!
ip classless
ip route 0.0.0.0 0.0.0.0 1.1.1.1
!
ip flow-export version 9
!
!
!
!
!
!
!
line con 0
exec-timeout 0 0
password 7 0822455D0A16
logging synchronous
login
!
line aux 0
!
line vty 0 4
login
!
!
!
end
ISP Router config
Current configuration : 996 bytes
!
version 12.2
no service timestamps log datetime msec
no service timestamps debug datetime msec
service password-encryption
!
hostname Router
!
!
!
enable secret 5 $1$mERr$hx5rVt7rPNoS4wqbXKX7m0
!
!
!
!
ip cef
no ipv6 cef
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
!
interface FastEthernet0/0
no ip address
duplex auto
speed auto
shutdown
!
interface FastEthernet1/0
no ip address
duplex auto
speed auto
shutdown
!
interface Serial2/0
ip address 1.1.1.1 255.255.255.252
!
interface Serial3/0
no ip address
shutdown
!
interface FastEthernet4/0
no ip address
shutdown
!
interface FastEthernet5/0
no ip address
shutdown
!
interface Serial6/0
no ip address
shutdown
!
interface Serial7/0
no ip address
shutdown
!
interface Serial8/0
no ip address
shutdown
!
interface Serial9/0
no ip address
shutdown
!
ip classless
!
ip flow-export version 9
!
!
!
!
!
!
!
line con 0
exec-timeout 0 0
password 7 0822455D0A16
logging synchronous
login
!
line aux 0
!
line vty 0 4
login
!
!
!
end
