Using Windows Remote Desktop with ipv6 router

Question

(asking here as it seems more appropriate than the main stack exchange)

I'm trying to use my home computer from work, since I am doing computational biology work that needs CPU power, and my i9 is about 4 times faster than anything I can use at work - my supervisor has recommended I remote, since the university is being stingy and we only have slow hardware at the office.

I tried setting up Windows Remote Desktop; I selected the options for enabling remote (My home PC uses Win10 Education, which seems to support it), and try to access it using a dynDNS (through No-IP).

The problem is that my router setup is ipv6: The connection came with my apartment and thus I have no ability to forward ports. All of the guides I can find on how to remote seem to rely on port forwarding, so I have no idea how to connect to my PC after I've connected to the dynDNS.

I am using NordVPN on my home PC, which I thought could have been an issue, but enabled or disabled I just can't connect.

The fact is I just don't know what I'm doing with regard to networking, especially ipv6 networking. I could do with a step by step guide here.

At the moment I'm using teamviewer, but given that my home PC has a much larger desktop resolution than my laptop, it just isn't practical having to zoom in on the text.

Answer 1

First note that IPv4 and IPv6 act as separate networks. If your workplace only has IPv4, then you cannot connect to a server that only has IPv6 – unless of course you first VPN into another network that has both IPv4 and IPv6. (This could be a commercial VPN provider, or a self-hosted VPN server.)

All of the guides I can find on how to remote seem to rely on port forwarding

The name of "port forwarding" is a bit misleading – it isn't something that allows a router forward packets between networks. (Forwarding packets is literally what a router already does.) Rather, it's a feature that redirects packets to a different destination.

examining the ISP's site said that ipv6 routers simply do not support port forwarding because a large block of ip addresses are assigned

That's your first hint. In IPv4, you're always connecting to the router's IP address, because the other home devices don't have a global address of their own. But the router has no idea what to do with this connection, so you use "port forwarding" (DNAT) to redirect it to another address in your LAN.

But with IPv6, the server computer also gets its own global address. As long as you're connecting to the computer's own address, the router already knows perfectly well which device to send the packets to, and "port forwarding" becomes unnecessary.

^{(IPv4-style port-forwarding and NAT is still technically possible in IPv6... but it's entirely useless, so nobody puts it in home routers.)}

However, even though your home router doesn't have NAT for IPv6, it should still have a firewall for IPv6.

Most likely, the router's firewall settings will be blocking all incoming connections by default. So even though it isn't called "port forwarding" anymore, you'll still need to create a very similar rule to allow traffic towards a specific address and port (except there aren't separate "internal" and "external" ports anymore).