Using the Command Line Interface
Steps to open port in CSF
1) Login to the server using the SSH.
2) Open the configuration file of the CSF as follows.
3) Add the required ports to the csf.conf file
# Allow incoming TCP ports TCP_IN = “20,21,22,25,26,53,80,110,143,443,465,587,993,995” # Allow outgoing TCP ports TCP_OUT = “20,21,22,25,26,37,43,53,80,110,113,443,465,873”
4) Restart the CSF for the changes to take effect. Run the below command to restart the CSF.