NAT and PAT with Packet Tracer

• Static NAT

  • Setting NAT interfaces

    • When setting up NAT you need to specify your internal and external interfaces. The internal interface (inside) would be for your lan and the external (outside) is your WAN. For this example we will use fast ethernet 1 as the internal network and fast ethernet 0 as the wan network.

    interface fa 0/0
    ip nat outside 
    interface fa 0/1 
    ip nat inside
    

  • commands for static NAT with example

    • You can map NAT statically so the same internal IP will always get a specific external IP. To do this you would run the following.

    ip nat inside source static 10.0.0.1 69.69.69.69
    

• Lab 5-2 NAT PAT

  • Commands to configure PAT with explanation so you can do it in future!

    • When configuring pat you need to grant access to a range. The following commands will setup PAT.

    ip nat pool PoolName RANGE-START RANGE-END netmask NETMASK
    access-list 1 permit IP CLIENT-NETMASK
    ip nat inside source list 1 pool PoolName overload
    
    ip nat pool PATPool 69.69.69.69 69.69.69.69 netmask 255.0.0.0
    access-list 1 permit 10.0.0.0 0.0.0.255
    ip nat inside source list 1 pool PATPool overload
    

  • Using Simulation Mode and protocol filters in Packet Tracer

    • Simulation mode allows you to see how the network traffic will flow. In this mode you can see where packets are getting dropped. You can also edit the filter list to only show specific traffic. So if you wanted to only see ICMP traffic in the network you could unselect all the other protocols in the filter.