my kcp port been closed! why?
i opening a KCP port for my server! but Linode closed it very quickly! this there any to put it to the white list or how to prevent the linode to close it?
1 Reply
tlambert
Linode Staff
You can ensure your Linode is not blocking connections to the port by allowing traffic via ip tables. You can also use UFW if it's installed.
To check the status of the port you can use nmap. This post titled How do I understand the results of an nmap scan? has instructions for using nmap and how to interpret the output.
Generally speaking, ports are only closed when a service is not running on them. For instance, your HTTP port (80) will be closed if there is no web server running on your instance. However, SMTP ports (25, 465, 587) are restricted on all new Linode accounts in an effort to fight spam.