If it is a remote server from Tencent or Alibaba, pay attention to configuring the security group. If the security group does not open the corresponding port, the server's open port will be useless.
Telnet uses the tcp protocol, so of course you will see that the connection failed. If your client cannot receive information, it is likely that the OUTPUT chain is blocked. So you need to release both the INPUT chain and the OUTPUT chain at the same time.
-A INPUT -p udp -m udp --dport 1193 -j ACCEPT
-A OUTPUT -p udp -m udp --sport 1193 -j ACCEPT
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If it is a remote server from Tencent or Alibaba, pay attention to configuring the security group. If the security group does not open the corresponding port, the server's open port will be useless.
Telnet uses the tcp protocol, so of course you will see that the connection failed.
If your client cannot receive information, it is likely that the OUTPUT chain is blocked.
So you need to release both the INPUT chain and the OUTPUT chain at the same time.