Hi,
I have been trying to configure static NAT on my network using a Cisco 1841 and slowly making progress. However, I am slightly stuck as I am unable to ping my public IP addresses on my internal network when using a static NAT. I have no problems at all when using a secondary IP interface and giving my server a public IP. I would prefer to use static NAT for my servers rather than assigning them public IP addresses as this wastes IP addresses due to the requirement of a gateway and network address aswell.
My configuration is as follows:
===
Router(config)#do show run
Building configuration...
Current configuration : 1657 bytes
!
version 12.4
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
!
hostname Router
!
boot-start-marker
boot-end-marker
!
no aaa new-model
ip cef
!
!
ip auth-proxy max-nodata-conns 3
ip admission max-nodata-conns 3
!
!
ip name-server 8.8.4.4
ip name-server 8.8.8.8
!
!
!
!
!
!
!
!
!
interface FastEthernet0/0
description Local Network
ip address 101.202.84.185 255.255.255.248 secondary
ip address 172.16.1.254 255.255.255.0
ip nat enable
ip virtual-reassembly
duplex auto
speed auto
!
interface FastEthernet0/1
description Public Network
no ip address
ip virtual-reassembly
duplex auto
speed auto
pppoe enable group global
pppoe-client dial-pool-number 1
!
interface ATM0/0/0
no ip address
shutdown
no atm ilmi-keepalive
dsl operating-mode auto
!
interface ATM0/1/0
no ip address
shutdown
no atm ilmi-keepalive
dsl operating-mode auto
!
interface Dialer1
ip address negotiated
ip mtu 1492
ip nat enable
ip virtual-reassembly
encapsulation ppp
dialer pool 1
dialer-group 1
ppp authentication chap callin
ppp chap hostname ********
ppp chap password 0 ********
!
ip forward-protocol nd
ip route 0.0.0.0 0.0.0.0 Dialer1
!
no ip http server
no ip http secure-server
ip nat source list ACL_NAT_LAN interface Dialer1 overload
ip nat source static 172.16.1.102 101.202.84.187
!
ip access-list extended ACL_NAT_LAN
permit ip 172.16.1.0 0.0.0.255 any
!
!
!
control-plane
!
!
line aux 0
line vty 0 4
login
!
scheduler allocate 20000 1000
end
When I assign 101.202.84.186 to my server NIC, I am able to access it from anywhere in the world including my internal network host of 172.16.1.1. However, if I try to access 101.202.84.187 as per this configuration, I am only able to access it from the outside world and not my host of 172.16.1.1.
If I remove the secondary IP from the Fa0/0 interface, then the IP of 101.202.84.187 is accessible on the internal network, but not outside of the network, and nor can the server of 172.16.1.102 access anything outside of the network.
Any advice or a nudge in the right direction would be much appreciated.
Kind Regards,
Jason.
