topic Re: Dynamic IP ISP NAT in General Topics

Dynamic IP ISP NAT

alexander.church — Wed, 17 Aug 2016 00:52:57 GMT

I'm trying to figure out how to NAT a single server and port to my external IP address if the outside interface from the ISP is dynamic. How do I translate it if I don't have a destination address?

Re: Dynamic IP ISP NAT

reaper — Wed, 17 Aug 2016 08:49:35 GMT

you could try mapping your external IP address (assuming it is dynamic) to a DynDNS service, then create a FQDN object you can use in the NAT policy

Re: Dynamic IP ISP NAT

TranceforLife — Wed, 17 Aug 2016 14:59:08 GMT

I am using this company for ddns. They are good, free ddns and support:

https://www.changeip.com

Re: Dynamic IP ISP NAT

alexander.church — Thu, 18 Aug 2016 03:20:26 GMT

Is me.me.me a server you're hosting?

Re: Dynamic IP ISP NAT

TranceforLife — Thu, 18 Aug 2016 10:29:46 GMT

No l am not hosting any servers. Got few UniFi controllers on AWS so using DDNS there, and for other things like you need to map dynamic ISP IP to have a constant DNS name.

Re: Dynamic IP ISP NAT

reaper — Thu, 18 Aug 2016 08:41:16 GMT

me.me.me is an example of an FQDN object you could have set up

it would represent a dyndns URL mapped to your external IP address

typically this would be a url specific to your dyndns provider, like me.dyndns.org which is dynamically mapped to your external IP, so when your ISP assigns you a fresh IP, dyndns will change the A record assigned to your url (me.dyndns.org), the PAN will refresh it's dynamic objects periodically (you could script a forced refresh if needed) and the NAT rule will be changed accordingly

An FQDN object allows you to rely on DNS resolution to populate an IP address in your policies rather than manualy setting a static ip, in case the IP tends to change a lot:

Re: Dynamic IP ISP NAT

alexander.church — Thu, 18 Aug 2016 14:13:29 GMT

I have that set up already. What I'm trying to do is present an internal server to the outside interface to access it from outside of the network. Since my address is dynamic, I'm not sure how to configure it in NAT.

Re: Dynamic IP ISP NAT

TranceforLife — Fri, 19 Aug 2016 18:49:05 GMT

Hi Alex,

You can try this:

1) Create an address object:

So you can run a DDNS agent (best option is to install it on the actual server) on the trust zone which constantly will be mapping/updating your outside dynamic IP to the www.myserverip.com DNS name.

More info here:

https://live.paloaltonetworks.com/t5/Configuration-Articles/How-to-Configure-and-Test-FQDN-Objects/ta-p/61903

2) Create a NAT policy for the internal server to be reachable from the outside. Really it is just a port forwarding

3) create a security policy for the server

Thx,

Myky

Re: Dynamic IP ISP NAT

alexander.church — Fri, 19 Aug 2016 14:20:51 GMT

Thank you for that, it worked. I was doing it a bit different and couldn't get it locked down. If anyone else wants to know, I also didn't have ping enabled, so the application that accesses the server wasn't moving forward. Funny thing, my internal server is also 10.10.10.10