Portforwarding setup correctly but not working.

[rhopkins]

Hi there,

My portforwarding using default HTTP settings is not working.

When connecting through the local host connection it works perfectly fine.

I have provided an image of my port forwarding settings.

[Debbie-TalkTalk]

Thanks for your help @KeithFrench 🙂

[KeithFrench]

Great, glad it is working. Many people get caught out by this. If you want to access the PI locally, use its 192.168.1.X address.

[rhopkins]

Oh, I tried on a VPN to change my IP and it works. Thank you so much!

[KeithFrench · Accepted solution]

Trying to establish a connection from a local device, out to the internet & back in again will be blocked by the router. TalkTalk does not allow the use NAT loopback traffic, as it is seen as a security vulnerability.

[rhopkins]

I am testing this by attempting to connect to the public IP and port that I forwarded to the Pi

This is my netstat -atup | grep "http" output

[KeithFrench]

I have just done some testing to Linux Mint where I opened TCP port 80, using this port forwarding rule:-

Port forwarding rule

The Linux Gufw firewall is set like this:-

Firewall

The test result:-

Port checker result

So if you can answer my questions in my previous post, we should be able to get this working.

[KeithFrench]

That's a pity about Wireshark, I was hoping that as the OS would seem to be Linux based it would let you install it.

Let's move back a bit, how are you testing this:-

1. Via a port checking website from a locally connected device
2. Via the internet
3. From another locally connected device to the Pi via its 192.168.1.x IP address.

If you run this command in Terminal, what output do you get:-

netstat -atup | grep "http"

[rhopkins]

Because I cant run wireshark because its on raspberry pi lite os

[rhopkins]

Would you like to see my Pi's IP tables instead?

[KeithFrench]

Is it set to listen on the 192.168.1.x IP address?

Can you run Wireshark on a Pi or some other .pcap capture utility, and then I will be able to analyse it to see where the problem is?

[rhopkins]

Also my port 80 on IP Tables is set to listen by apache

[rhopkins]

It should be

[KeithFrench]

Then have you allowed TCP port 80 through it in an inbound direction?

[rhopkins]

Yes

[KeithFrench]

Is there a firewall on your Pi?

[rhopkins]

Please could I have some help with this as I am quite new to it.

The device I am trying to port forward is a Raspberry Pi 2B

[KeithFrench]

Hi @rhopkins 

@Karl-TalkTalk has brought this to my attention. There is nothing wrong with your port forwarding rule in your router. However, have you added an inbound rule to your device's firewall? Assuming this is a Windows PC, the Defender Firewall (unless you use a different one) requires a configuration change to allow this port.

I can help further with this if required, but I will need to know what sort of device this is.

[Karl-TalkTalk]

Hi

Have a read through the info at How To Set Up Port Forwarding - Port Forward

This can help if you are setting up a port forwarding for a specific application etc.

Our resident Community Expert @KeithFrench can also offer great insight when is comes to setting this up and may also be able to offer more advice.

Karl.