two way NAT on cisco ASA

[mig25r]

Hello,

In a network setup, we require to use the same public IP for both outbound traffic & inbound traffic for services with a private 172.16.1.2 address on an ASA.

172.16.1.2 ----> Internet : should use public x.x.x.x
Internet ------> 172.16.1.2 : should use same x.x.x.x public

that is both ways the public ip used should be the same with this private ip.

It will be helpful if someone can guide, on how it can be achieved.

Thank You.

 

[Noway2]

Welcome to tek-tips.

The setup you desire is relatively easy, but it will take a few co-ordinated steps.

First, you will want to ensure that your PUBLIC dns points to the PUBLIC IP associated with your router. In this instance I say router, but I mean whatever device you are using for your private / public gateway. This will cause legitimate traffic to go to that IP address.

Second, you will need to put up inbound firewalls on all other inbound PUBLIC IP addresses. There is no way in naming to prevent someone from trying to scan or access them if they are there and active.

Third, in your LAN DNS configure the LAN gateway as the PRIVATE IP of your gateway. This will effectively bridge your public and private IP address, causing that IP set to be used for all traffic.

Fourth, you will need to port forward from your gateway any services that you want to operate on your LAN, such as email, web, etc. The port forwarding will point to the private IP of the device that is hosting the service.

Fifth, you will want to put up outbound firewalls on any active, public facing IP addresses, to prevent someone from attempting to use it as the gateway.

This type of setup is also common in residential applications where there is only one access pipe and a basic router is used to perform NAT between the two domains.

 

[mig25r]

thanks for helping with that. But what i am actually looking for is specific configurations that requires on ASA , when the same public ip will be used only by a specific local ip for outbound and the same public ip will be used for web service hosted on the same private ip for incoming traffic from internet to this private ip server.