Why is my computer not accessible to the entire Internet?

Question

Computer networks

Hello. I wanted to create a server to play with friends. Faced a problem.

I forwarded ports on my router. Enabled the DDNS function. It seems everything should work, but my server is available to some users (we are within 4km from each other), and to some it is not (1 lives in about 20km, the second in about 8). What should be done ?

PS For those who cannot connect, ping or does not see my node, or 100% loss.

Answer 1

Do you have a white (external) IP?
if not, then most likely those who have the same provider can connect.
others require a white IP on your side, otherwise they will not connect to you

Answer 2

Because you are in different network segments. DDNS does not solve this problem.
Or your clients do not have access to DDNS servers.
Let them try to connect by IP address.

Answer 3

an important question, are people who are 4 km away connected to your local network or not (via provider or vpn)?
if so, does it mean that something in the question did not finish and the ip address is used from the local network?
dyndns is just an automatic domain name assignment of your changeable ip address with minimal delay (by means of a router for example)
is the ip address resolved correctly by the name used by dns? those. Is it the same for those who work and who do not?
first you need to check the performance simply by the ip address (even if it is issued for a short time for hours or days)
if the ip is correct and does not work, then you can safely stomp to the provider, in Russia the Internet has long been broken and providers really 'love' not obvious blockages and jambs