Help Needed on Port Forwarding

this is my current situation …
my IP is dynamic and therefore always changes.
in the internal network I have set a fixed ip for the mac where Roon resides and ARC does not activate
also place the configuration of the modem router where you see the port 55000 and under the IP of the mac where there is roon
post a photo of my IP
and one of the ISP where it indicates the mode of access to the outside.
that’s why (I think) I need a public IP to connect ARC outside my home.

Schermata 2022-09-26 alle 09.49.51

this is what i see on the cell if i disable wifi … so i go with my ISP’s external network …
can’t connect with roon core

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Right, but the fact that you have two modems leads you to this “Multiple NAT” error.
Roon gives in their manual some possible solutions (bridging the modems is one of them, but not always easy and not always possible).
Another solution is to do some port forwarding in both modems:
First, you need a P.F. from the external ISP address ( to the internal IP address of you ISP modem ( Then, in your second modem, you also need a P.F. from that last address to your Roon Core (
This could help solve the double NAT issue.

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I don’t have two modems … I have a modem and a network switch (a tp-link SG105E)
not quite understood what I should do on the switch :roll_eyes:

here the switch settings

am I wrong something?

Hmmm…a setup that is not in my text book… :slight_smile:

I see three IP’s:,, and…
Where do they come from?

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the first is the IP that ISP assigns me from time to time when I connect to the network.
the second is (probably) always assigned by ISP but I can’t get involved.
the third is the IP that I assigned to the mac mini where roon core resides, it is a fixed IP within the home network.

already tried with 60000-62000-65000 but the result does not change unfortunately.

LOWER than 16000

But you have the error of Multiple NAT, meaning you have two devices between the ISP and your Mac that provide NAT. First of all that’s your ISP modem, and second, that is…what?

sorry … I put a 0 too many :blush:

Then I’ll hush…not able to help ya…

I don’t know what the answer is … I don’t know what that IP that starts with is …

it is the IPV4 that assigns the ISP, but it changes (obviously) at each access …

…however I asked the manager to have a public IP.

@Lanfranco_Giordano - I think it would be better to split your issue off into a new Support request, so that the Support team can give it some attention. This thread of JST1963 has been marked as solved, so the team will be looking at other support requests now. I can move your posts, and their replies, for you. OK?

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yes of course … indeed sorry for too many posts :pray:

Hi @Lanfranco_Giordano,

I’d like to take a look at this with you. Can you please provide the make and model of your modem? Do you also have a router? If so, please provide the make/model there as well.

Wes = public IP = could be private address assigned for CGNAT = private address of the roon core

That could be CGNAT, ISPs don’t always use the correct address range for them

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thank you.
I state that my ISP (fastweb) assigns shared private addresses and only on request (like the one made today by me) assigns public addresses, the problem is just that, I hope to solve it as soon as they assign me a public IP.
however the modem is a fastgate (I am attaching photos taken on the net, there is no precise model but a single model owned by fastweb)

and this is the tp-link switch i use for pc, for Roon and for audio playback software (2 machines)

Hi @Lanfranco_Giordano,

From what I can tell from my research, you definitely need a public IP. As @ChrisRoon mentioned, please look at the article in his post.

This is what I found when I looked up your modem:

This is from the article below:

" Get a public IP

The Fastweb network is very different from that provided by the other operators: normally all users are connected to a network with shared IPs, so it is not possible to open a specific door and be reachable from the outside, since we are present inside an untangled and complex network (remote services would not know which modem to point to).
To be able to proceed with the correct forwarding of the ports, we will have to request assistance, requesting to obtain a public IP of Fastweb (ie an address assigned only to us and accessible from the outside as already explained in another post).

The easiest way to get this IP is to call the phone number 192193 (from Fastweb fixed line or from Fastweb SIM), follow the commands of the voice guide and talk to an operator, so as to be able to advance the request."


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