ONE External IP to MANY Internal IP NAT

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L2 Linker

ONE External IP to MANY Internal IP NAT

I believe I know the answer after looking around.

We have NATs that work fine when it is 1to1.

But what about  1 External IP that represents many Internal Hosts?  We have multiple websites that when you do a lookup in DNS, they all point to a singular public facing IP.  That public facing IP is represented by our ISA.

External                                             Internal

mysite.org - xxx.xxx.67.18          >  192.168.1.20

mysite1.org - xxx.xxx.67.18        >  192.168.1.21

mysite2.org - xxx.xxx.67.18        >  192.168.1.22

Could this be done by changing addresses (Objects > Addresses) to use FQDN instead of IP?

So the thought there would be:

2 New Objects

------------------

Name: mysite.org (outside) - FQDN: mysite.org

Name: mysite.org (inside) - IP Address: 199.168.1.20

NAT Policy

-----------------

Src: untrust

Dst: untrust

Src Addr: Any

Src Addr: mysite.org (outside)

Dst Addr Translation: mysite.org (inside)

Security Policy

-------------------

Src: Any

Dst: mysite.org (outside)

Thoughts?

L7 Applicator

Re: ONE External IP to MANY Internal IP NAT

Hello greeng,

The above mentioned setup will work fine if you are running internal servers on different port. For an example:

External                                             Internal

mysite.org - xxx.xxx.67.18 Port-80         >  192.168.1.20 -port-80

mysite1.org - xxx.xxx.67.18  port-8080      >  192.168.1.21 -port-8080

mysite2.org - xxx.xxx.67.18  port-443      >  192.168.1.22 port 443

NAT/security policy should be configures as mentioned below:

Name: mysite.org (outside) - FQDN: mysite.org

Name: mysite.org (inside) - IP Address: 199.168.1.20

NAT Policy

-----------------

Src: untrust

Dst: untrust

Src Addr: Any

Service: http/https or custom service

Destination Addr: mysite.org (outside)

Dst Addr Translation: mysite.org (inside)/192.168.1.21/192.168.1.22

Security Policy

-------------------

Src: Any

Dst: mysite.org (inside)

Hope this helps.

Thanks

L0 Member

Re: ONE External IP to MANY Internal IP NAT

Hi greeng,

The mentioned setup will work if you are running internal server with different private IP address. Please find the below example for the same.

External                                             Internal

mysite.org - xxx.xxx.67.18 Port-2000         >  192.168.1.20 -port-80

mysite1.org - xxx.xxx.67.18  port-2001      >  192.168.1.21 -port-80

mysite2.org - xxx.xxx.67.18  port-2002      >  192.168.1.22 port 80

NAT/security policy should be configures as mentioned below:

Name: mysite.org (outside) - FQDN: mysite.org

Name: mysite.org (inside) - IP Address: 192.168.1.20

NAT Policy

-----------------

Src: untrust

Dst: untrust

Src Addr: Any

Services : External Port ( Ex : 2000, 2001, 2002)

Destination Addr: mysite.org (outside)

Dst Addr Translation:  mysite.org (inside)

Dst port : 80

Security Policy

-------------------

Src: untrust

Dst: trust

Dst addr : mysite.org (outside)

Regards,

Sarath

L2 Linker

Re: ONE External IP to MANY Internal IP NAT

Thank you HULK and sbabu

I'm going to do some testing.

L7 Applicator

Re: ONE External IP to MANY Internal IP NAT

You are welcome. Let us know how it goes :smileygrin:

Thanks

L0 Member

Re: ONE External IP to MANY Internal IP NAT

Also you can use the below document for your reference

Understanding PAN-OS NAT

Page 19& 20

Thank you.

L4 Transporter

Re: ONE External IP to MANY Internal IP NAT

I agree with Hulk.

The only way you can do a "1 to many" NAT is via PAT.  You must set up separate ports for each connection.

Highlighted
L6 Presenter

Re: ONE External IP to MANY Internal IP NAT

This video tutorial will help you with the DNAT configuration.

Video Link : 1550

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