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Linux is a family of open source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991 by Linus Torvalds. Linux is typically packaged in a Linux distribution (or distro for short).
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I’m guessing that your computer doesn’t have its own public IP address, so, opening ports on its firewall doesn’t actually make them reachable on the internet yet. You’re probably behind a NAT gateway (eg, the modem/router your computer is connected to the internet via), so you need to open a port there and direct it to your computer.
NAT allows your whole LAN to share a single public IPv4 address, which means that for inbound connections the gateway needs to be configured to know which LAN address to send inbound traffic on a given TCP/UDP port to.
On your linux computer you can find out the IP address of your router with the command
ip route |grep default
, and then you can browse to that address in your web browser. You’ll most likely need its password (maybe it’s written on the bottom of your router/modem?). Once you’re logged in to its web interface, you’ll hopefully be able to figure out how to use it to open/allow/map/route ports to your computer.edit: it looks like the URL you’re using to test is referring to a different port than any of the ones you said you’ve opened with
ufw
, which might be a problem? also, btw, theufw allow
command takes effect immediately - you don’t need tosystemctl restart ufw.service
afterwards.deleted by creator
Are you running the software that you want to be listening on that port while you’re doing the test? Are you sure it is actually listening on that port? You can see which ports which programs are listening on with the command
sudo ss -tulpn
(those options tell it to display tcp and udp listening ports and program names, and to not try to resolve IP addresses into names; seeman ss
for details).If you’ve opened the port in your gateway and your local firewall and you’re running the software, it seems like it should work… one possible reason why it might not would be if you’re double NAT’d (eg the NAT gateway you’re configuring is itself behind another NAT gateway). To see if this is the case, try to find in the router’s web interface if it says what its WAN (upstream) IP address is. If it’s something else in an RFC1918 range (192.168.x, 10.x, or 172.16-31.x) then you’re double NAT’d and need to figure out how to configure the outer NAT gateway.
deleted by creator