Port Forwarding

[an00p]

I have realized that my wan IP is different from my public IP . Is this the reason why port forwarding never works for me? Is there a way to solve this? When I got in touch with my ISP they said that they do not block any ports.

[Tabs]

In what way are your wan IP and public IP different?

 

So long as the traffic is being directed to your router, you should be able to forward it to a device regardless of the IP address.

 

This could be a result of CGN.

[an00p]

Yes I thing this is due to NATing but my public IP keeps changing.

should I use a dns as a workaround?

[Tabs]

3 minutes ago, an00p said:

Yes I thing this is due to NATing but my public IP keeps changing.

should I use a dns as a workaround?

Your externally-assigned address shouldn't change unless your ISP uses dynamic IP's (many do), but it should also not happen unless your router or modem is turned off.

 

How often does it change? What are you using to check your address? I recommend https://icanhazip.com/ as it's a good, scriptable external ip reference.

[an00p]

it change almost every 24 hours

[Tabs]

2 minutes ago, an00p said:

it change almost every 24 hours

Well, either way, it shouldn't affect port forwarding - the idea of port forwarding is that a port gets opened on the WAN side of the router interface, and it gets forwarded to an IP/port on the LAN side. So long as the client computer you're forwarding to has a static IP address, there's no reason port forwarding shouldn't work even if your external IP address changes.

 

If you're trying to host a service, then you might have no choice but to use a dynamic dns address like you suggested. If your router/modem isn't rebooting on a schedule every night or anything else, you might have no choice. 

[an00p]

I will try using a dns .

Thank you

[homeap5]

Your WAN IP is different thatn your public IP because you don't have external IP. And because of that, none of port forwarding will work in your case.

 

This is situation when your ISP has not enough IP addressess and uses internal IP range for increase number of users. Ask your ISP is it possible to get external IP. Sometimes it will require additional payment.

 

Your ISP probably not blocks ports as they says, but may have disabled other functions like UPNP or you just spoke with someone who was not technician and answers you anything (people rarely answers "I don't know").

 

10.0.0.0 – 10.255.255.255
172.16.0.0 – 172.31.255.255
192.168.0.0 – 192.168.255.255

 

These IP ranges are using for internal IP, so check your "WAN IP" - if it looks like 172.18.12.245 or 10.2.124.210 then you're sure that you have no external IP.

Of course there is no limitation with creating any of IP ranges for internal network - you just lose possibility of using some part of internet.

[Alex Atkin UK]

Sounds like your ISP might be using CG-NAT, you would need to see if they will assign you a proper public IP if you need port forwarding to work.