How to open ports in Debian?

Question

linux

I bought vds in hatzner to open ports
iptables -t filter -A INPUT -p tcp --dport 19132 -j ACCEPT

When a site connects via rcon to a service, for some reason debian blocks the incoming connection

tcp        1      0 0.0.0.0:19132           0.0.0.0:*               LISTEN      12725/PocketMine-St
tcp       25      0 95.217.219.25:19132     31.31.196.102:41742     CLOSE_WAIT  -
tcp        1      0 95.217.219.25:19132     31.31.196.102:38954     CLOSE_WAIT  12725/PocketMine-St
udp        0      0 0.0.0.0:19132           0.0.0.0:*                           12725/PocketMine-St

Tell me what to do?

Answer 1

show the output of iptables -L INPUT -vnx

Answer 2

And the connection can be blocked by the application on 19132/tcp? Like listen port? You obviously work on ssh. SELinux?

Answer 3

Try ufw, the firewall is like that. sudo apt update && sudo apt install ufw then ufw allow 19132