Need help with setting up a full node

I set up the DHCP on my modem/router to give my PC a static IP. NAT is configured to forward port 8333 to that PC. I also set the firewall to "low" to allow connections. In Windows, I made the necessary firewall rule. But my full node isn’t working since port 8333 seems to be closed. What am I doing wrong?

Did you also set a firewall exception in your router?

Did you mean port forwarding is configured?

Please be specific on the way that it's not working. Like, not connecting at all or has outbound connections but no inbound connections? Because if it's just about failing to open port 8333, your node should've at least outbound connections. If it's not connecting to any peer, try to check your "debug.log" file for related errors because it could be caused by something else. Your debug.log file is in your bitcoin datadir.

What happens if you try to connect to port 8333 - from your own computer - from some other computer on the same LAN - from the rest of the Internet? The answers to these questions will help you to determine which part has not opened up port 8333 yet. You can use a program like nmap to check (set it to only check port 8333).

Just learned there's a issue with my ISP. Basically i can't do what i want if i don't pay. Perfect I suppose running Bitcoin Core without port 8333 is useless for the network, is it?

How about a VPN with port forwarding (or a cheap VPS with OpenVPN installed)?

I wouldn't say that it is useless, at least you're doing more than most. Per my understanding, port 8333 is meant for inbound connections which is the channel that allows other nodes to connect to your own node but in the event that you are not able to open the port, you still provide the network with some benefits, per Greg Maxwell reply here[1]: Would it be optimal for the node to have its inbound connection port open? Yes, but if you are indeed unable to do it, you are still, in a way, contributing to the network. [1]https://bitcoin.stackexchange.com/questions/88127/are-nodes-that-dont-accept-inbound-connections-necessarily-leechers/88147

That's great then. I'm sorry for the inbound connections but i'll help with the outbound then. Thank you for the clarification.

Do note LoyceV reply before mine as I think that it's an interesting path to explore if you're willing to. I recommend the second approach (VPS with OpenVPN) and you can follow this[1] guide in order to have it up and running. Most well regarded VPN providers - such as Mullvad or IVPN - have removed the ability to do port forwarding. Proton still allows it[1] but you have to be a paid subscriber and you also get the port chosen by the program and you have to change it each time you restart the VPN connection. Considering that I personally do not trust other VPN providers, my recommendation would be the second option (VPS with OpenVPN installed). [1]https://monovm.com/blog/how-to-install-openvpn-on-vps/ [2]https://protonvpn.com/support/port-forwarding/

Generally VPN over VPS is rather slow, and also more expensive with insufficient benefits to the network. Instead of having one hop, data goes through your VPS and then to your computer. Cheap ones are generally quite slow and likely wouldn't have sufficient bandwidth for a very large node. 1TB upload is probably not very sufficient if you have a VPN running through it and nodes connecting to it. It shouldn't be an issue if you're unable to accept inbound connections. If you want an easy to setup and a free solution, then you can route it through Tor.

Back in the day when I was running a node [v22], I got a similar response from one of my ISP's support staff [e.g. you need to upgrade blah blah blah], but I still managed to find a workaround [with uTorrent] and a solution [turning on UPnP (credit goes to @ranochigo)]: Can't get inbound connections on Bitcoin Core! [Solved]

Name and shame the ISP. This way the next person who has this same issue will know it's not them it's their ISP. Assuming they search the forum for the ISP name and / or one of us remembers this thread. -Dave

If port forwarding is a premium service on OP's side, then this is a clever workaround for it. However, my recollection is that by having UPnP enabled ends up being a security risk considering that you are basically allowing anything within your device to open ports directly into your firewall. If you end up having malware on it, then it can quickly spread to the remaining (vulnerable) devices in the network. Note that I haven't messed around with UPnP for ages, perhaps the protocol developed more since last time I tinkered with it...

Unfortunately, I didn't pay enough attention to its consequences when I was running a node in the past [SMH] until I read your comment and did some Googling... It appears that you're right [it looks like I'll be sticking with outbound connections whenever I decide to run a node again (thank you)]. - For those who might be interested, here are two old threads (#1 and #2) with interesting arguments about it.

Glad that I could help. UPnP and DMZ are one of those things that shouldn't ever be touched considering the security holes that they end up creating in a user network. I have to say that I had never heard of having to pay a premium for port forwarding capabilities, but I reckon that nowadays ISPs are always looking for ways to charge customers functions that should be made available freely. In case some guidance is needed for whoever is reading this, I always share this[1] website for people looking to port forward - it has a large array of suppliers and it covers the needed steps for someone to successfully port forward (assuming the ISP isn't greedy...). [1]https://portforward.com/router.htm

The Bitcoin network does not only check port 8333 for P2P connections. When it gets the list of peers from another node, or in the case where there are no other known nodes, then from hard-coded seed nodes, it receives the port number along with the IP address. That way, you are able to set the listening port to be whatever you want it to be, and still receive incoming connections as long as your network is configured correctly.

OT a bit but with the IP4 network address exhaustion: https://en.wikipedia.org/wiki/IPv4_address_exhaustion https://lightyear.ai/blogs/what-ipv4-address-exhaustion-means-for-you More and more ISPs are using CGNAT for home customers: https://nfware.com/blog/what-is-the-difference-between-nat-and-cgnat#:~:text=CGNAT%20(Carrier%2DGrade%20NAT),a%20single%2C%20public%20IP%20address. So there is no port forwarding since you are more or less already on a 'private network' Some ISPs are dong a hybrid with your IP4 address coming through CGNAT but you also get a real pubic IP6 address that you can use. So, yeah it's happening. Starlink is a prime example of this people ran out to get it and then discovered a bunch of things that need static port mappings no longer work. -Dave