Dynamic NAT Overload exercise understanding the problem.

[jose.rodriguez.an]

Hi all,

I'm doing a practice with packet tracer to configure a Dynamic NAT overload (or PAT). 

In this practice, I have to create a Dynamic NAT overload with the following information:

IP public address 65.0.0.15

and the router_principal  

Gig0/0 30.0.0.1/8
Gig0/ 216.0.0.1/24

The router_principal has this running_config

Router_Principal#sh running-config
Building configuration...
Current configuration : 888 bytes
version 15.1
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname Router_Principal
!
ip cef
no ipv6 cef
!
license udi pid CISCO1941/K9 sn FTX1524247V-
!
spanning-tree mode pvst
!
interface GigabitEthernet0/0
 ip address 30.0.0.1 255.0.0.0
 ip nat outside
 duplex auto
speed auto
!
interface GigabitEthernet0/1
 ip address 216.0.0.1 255.255.255.0
 ip nat inside
 duplex auto
speed auto
!
interface Vlan1
 no ip address
 shutdown
!
ip nat pool dhcp_publicas 65.0.0.15 65.0.0.15 netmask 255.0.0.0
ip nat inside source list 10 interface GigabitEthernet0/1 overload
ip classless
ip route 0.0.0.0 0.0.0.0 GigabitEthernet0/0
!
ip flow-export version 9
!
!
access-list 10 permit 192.168.0.0 0.0.0.255
!
!

The private network is 192.168.0.0/24

The soho_router 

Router_SOHO#sh running-config
Building configuration...
Current configuration : 679 bytes
!
version 15.1
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname Router_SOHO
!
ip cef

no ipv6 cef
!
license udi pid CISCO1941/K9 sn FTX1524BLRG-
!
spanning-tree mode pvst
!
interface GigabitEthernet0/0
 ip address 30.0.0.2 255.0.0.0
 duplex auto
 speed auto
!
interface GigabitEthernet0/1
 ip address 192.168.0.1 255.255.255.0
 duplex auto
 speed auto
!
interface Vlan1
 no ip address
 shutdown
!
ip classless
ip route 0.0.0.0 0.0.0.0 GigabitEthernet0/0
!
ip flow-export version 9
!
line con 0
!
line aux 0
!
line vty 0 4
 login
!
!
!
end

I can ping to and from any due to default ip route in both routers.

But at the time to write

sh ip nat translation and s ip nat statistics

, seems that nat has not been created.

Router_Principal#sh ip nat translations
Router_Principal#
Router_Principal#sh ip nat statistics
Total translations: 0 (0 static, 0 dynamic, 0 extended)
Outside Interfaces: GigabitEthernet0/0
Inside Interfaces: GigabitEthernet0/1
Hits: 0  Misses: 0
Expired translations: 0
Dynamic mappings:
-- Inside Source
access-list 10 pool dhcp_publicas refCount 0
 pool dhcp_publicas: netmask 255.0.0.0
       start 65.0.0.15 end 65.0.0.15
       type generic, total addresses 1 , allocated 0 (0%), misses 0
Router_Principal#

I don't know what I am doing bad, I watched youtube videos to understand but with no positive results.

I attached packet tracer file in case someone can help me to solve and explain why exists this problem !!!

Thank you in advance

[Jon Marshall · Accepted solution]

You are not using the pool you have created in your NAT statement. 

Jon

[Georg Pauwen · Accepted solution]

Hello,

your configuration looks mixed up:

interface GigabitEthernet0/1
ip address 216.0.0.1 255.255.255.0
--> ip nat inside
duplex auto
speed auto




--> ip nat inside source list 10 interface GigabitEthernet0/1 overload

What instructions are you following ? Post the zipped project (.pkt) file together with the written instructions you are following...

[jose.rodriguez.an]

Hi Georg,

Sorry for the delay to answer, I haven't received any email about my question from cisco community.

Thank you for your reply and help. At least PAT is working, I have took a lot of videos and read pdfs to see the issue, and I couldn't  make work. There's no ping between networks. Despite I configured both routers with a default route 

ip route 0.0.0.0 0.0.0.0 GigabitEthernet0/0

, strange but it is enough.

This is the configuration from Router_SOHO

!
hostname Router_SOHO
!
ip cef
no ipv6 cef
!
license udi pid CISCO1941/K9 sn FTX1524BLRG-
!
spanning-tree mode pvst
!
interface GigabitEthernet0/0
 ip address 30.0.0.2 255.0.0.0
 ip nat outside
 duplex auto
 speed auto
!
interface GigabitEthernet0/1
 ip address 192.168.0.1 255.255.255.0
 ip nat inside
 duplex auto
 speed auto
!
interface Vlan1
 no ip address
 shutdown
!
ip nat pool dhcp_publicas 65.0.0.15 65.0.0.15 netmask 255.0.0.0
ip nat inside source list 10 pool dhcp_publicas overload
ip classless
ip route 0.0.0.0 0.0.0.0 GigabitEthernet0/0 
!
ip flow-export version 9
!
access-list 10 permit 192.168.0.0 0.0.0.255
line con 0
!
line aux 0
!
line vty 0 4
 login
!
end

Configuration Router_Principal

Router_Principal#sh running-config 
Building configuration...

Current configuration : 876 bytes
!
version 15.1
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname Router_Principal
!
ip cef
no ipv6 cef
!
license udi pid CISCO1941/K9 sn FTX1524247V-
!
spanning-tree mode pvst
!
interface GigabitEthernet0/0
 ip address 30.0.0.1 255.0.0.0
 ip nat outside
 duplex auto
 speed auto
!
interface GigabitEthernet0/1
 ip address 216.0.0.1 255.255.255.0
 ip nat inside
 duplex auto
 speed auto
!
interface Vlan1
 no ip address
 shutdown
!
ip nat pool dhcp_publicas 65.0.0.15 65.0.0.15 netmask 255.0.0.0
ip nat inside source list 10 pool dhcp_publicas overload
ip classless
ip route 0.0.0.0 0.0.0.0 GigabitEthernet0/0 
!
ip flow-export version 9
!
access-list 10 permit 216.0.0.0 0.0.0.255
!
line con 0
!
line aux 0
!
line vty 0 4
login
!
end