CISCO Home Lab Router not NATing [closed]

Question

I hope someone can help me. I have a AT&T 2wire gateway with a cisco router attached to port 3 of the AT&T 2 wire. I'm using the CISCO as a separate network and lab. Below is sketch of my network and the show run config output of the router. My problem is that I'm trying to use NAT to get to the internet from the cisco router through the AT&T wire. Also when I do a show nat translation does not nothing shows in the table as if nothing is being translated and I cannot get to the internet but can ping everything on both networks, 10.1.1.0. 192.168.1.0. Where am I going wrong.

AT&T 
  |
  |
192.168.1.111
  |     fa0/0 Outside NAT
  |
   CISCO Router
              fa0/1 10.1.1.1 Inside NAT



    Router#show running-config
    Building configuration...

    {Current configuration : 1039 bytes
    !
    version 12.3
    service timestamps debug datetime msec
    service timestamps log datetime msec
    no service password-encryption
    !
    hostname Router
    !
    boot-start-marker
    boot-end-marker
    !
    !
    no network-clock-participate slot 1
    no network-clock-participate wic 0
    no aaa new-model
    ip subnet-zero
    ip cef
    !
    !
    ip dhcp excluded-address 10.1.1.1 10.1.1.10
    !
    ip dhcp pool Test_Lab
       import all
       network 10.1.1.0 255.255.255.0
       default-router 10.1.1.1
    !
    !
    !
    !
    !
    !
    interface FastEthernet0/0
     ip address 192.168.1.111 255.255.255.0
     ip nat outside
       duplex auto
     speed auto
    !
    interface Serial0/0
     no ip address
     shutdown
     !
    interface FastEthernet0/1
     ip address 10.1.1.1 255.255.255.0
     ip nat inside
     duplex auto
     speed auto
     !
     ip nat inside source list 101 interface FastEthernet0/0 overload
     ip http server
     ip classless
     ip route 0.0.0.0 0.0.0.0 192.168.1.0
     ip route 10.1.1.0 255.255.255.0 FastEthernet0/0
     ip route 10.1.1.0 255.255.255.0 192.168.1.0
     !
     !
    access-list 101 permit ip 10.1.1.0 0.0.0.255 any
    !
    line con 0
    line aux 0
    line vty 0 4
    login
    !
    !
    end






Router#show ip route
Gateway of last resort is 192.168.1.0 to network 0.0.0.0
 10.0.0.0/24 is subnetted, 1 subnets
 S       10.1.1.0 is directly connected, FastEthernet0/0
   [1/0] via 192.168.1.0
 C    192.168.1.0/24 is directly connected, FastEthernet0/0
S*   0.0.0.0/0 [1/0] via 192.168.1.0

Changed ip route to AT&T PORT IP ADDRESS WHICH CISCO ROUTER is cabled to

    Gateway of last resort is 192.168.1.93 to network 0.0.0.0

     10.0.0.0/24 is subnetted, 1 subnets
C       10.1.1.0 is directly connected, FastEthernet0/1
C    192.168.1.0/24 is directly connected, FastEthernet0/0
S*   0.0.0.0/0 [1/0] via 192.168.1.93

Answer 1

I would assume that the problem is in your routing table. E.g.,

ip route 10.1.1.0 255.255.255.0 FastEthernet0/0
ip route 10.1.1.0 255.255.255.0 192.168.1.0

According to these commands, all IP packets to 10.1.1.0 network will be redirected either to FastEthernet0/0 (which means back to 192.168.1.111) or to 192.168.1.0 (which probably means nowhere, since this is address of the network, not an address of a gateway). So no IP packet could reach 10.1.1.0 network.

However, I'm not sure if this is a problem, since 10.1.1.0 is directly connected and it still could work correctly. Could you please add your routing table to the question (Output of 'sh ip route')?

Answer 2

Im guessing the AT&T has a LAN side IP address, in which case you need to create a default route on the cisco router that sends all traffic with a destination of unknown networks to the lan side interface on the AT&T box.

ip route 0.0.0.0 0.0.0.0 IPOFAT&TLANINTERFACE

This means the next hop of any 'unknown network' traffic such as traffic to the internet will be directed to the AT&T router which in turn fowards the traffic to its upstream gateway.

You do not need to perform NAT on the cisco unless you can operate the AT&T in bridge mode and assign your public IP to an interface on the cisco.

Answer 3

Might be that I've misunderstood your problem but it sounds like you can't even ping destinations on the Internet from your Cisco router which then would be the main problem and not NAT. Since you can see translations with "show ip NAT translations" it sounds like that part of the config is fixed.

Try to ping destinations on the Internet from a source interface of Fa0/0. Do you have other devices apart from the Cisco router connected to the AT&T device and can they reach the Internet?

Edit: Seems like you've used the wrong IP for default gateway. To find the correct IP you can either use the Laptop or the Cisco Router.

On Laptop: Connect it to the network and make sure it has DHCP turned on and not static IP. Use ipconfig to display your assigned Default Gateway next to your assigned IP address. Might look similary to this or it could display more information but regardless you should be able to find the address for your default gateway in the output from ipconfig.

https://i.stack.imgur.com/ezGAF.jpg

Use the IP of the default gateway for your static route on the cisco router.

Alternative 2: On Cisco router you could do the same thing:

enable
configure terminal
interface FastEthernet0/0
ip address dhcp
exit
no ip route x.x.x.x (make sure to remove every static route in your config just to have a more clean config)
end
show ip route

In the output you should see Gateway of last resort is x.x.x.x and that is the IP of your AT&T inside interface

When you have found which IP is your gateway you can switch back to static IP for your router and use that IP as a default route.

Answer 4

I created a static route to the public IP Address on interface fa0/0. When I do a show ip int brief on the cisco router, I get a 192.168.1.254 IP address.

I connected a laptop to interface fa0/1 received a 10.1.1.1.11 as IP address from DHCP on the CISCO router and I'm able to get out on the internet. So look like its working.