How do I setup FTP on CentOS 7
Linode
Linode Staff
I want to run an FTP server on my Linode and open port 21 on my firewall to upload my web pages using an FTP client. How do I do this?
1 Reply
hphillips
Linode Staff
Warning!
Using the FTP protocol is insecure. Anyone who as control of the network between you and your server will have access to your passwords used to login. Additionally any files transmitted over the network can be read and even changed in transit. For this reason, I strongly recommend that you use SFTP where possible. It which runs over an SSH connection and provides end to end encryption for both your credentials and your data.
Update your repositories and install your FTP server
sudo yum update
sudo yum install vsftpd
Start and configure your FTP server to run at boot time
sudo systemctl start vsftpd
sudo systemctl enable vsftpd
Understanding how FTP works
Using FTP uses separate channels for commands and data. In addition it has two modes, active and passive.
Active Mode
When using active mode, the
- FTP client sets up the command channel by using a random port to connect to port 21 on the server.
- The FTP client picks another random port and tells the FTP server to send data back on that port.
- The FTP client then starts listening for the data on that port.
- The FTP server sets up a data channel back to the client from port 20 to the port that the client said it was listening on.
If your local firewall does not allow incoming connections, you will not be able to use active mode FTP.
Passive Mode
Passive mode relies on the client to setup both channels
- The FTP client sets up command channel from a random port to port 21 on the FTP server.
- The FTP client then sets up the data channel from another random port to port 20 on the server.
Allowing your Linode to keep track of FTP connections
sudo modprobe ip_conntrack_ftp
sudo nano /etc/sysconfig/iptables-conf
Look for a the line that has IPTABLES_MODULES=, change it to say:
IPTABLES_MODULES="ip_conntrack_ftp"
Restart your iptables
systemctl restart iptables
Setting up your firewall
This article explains the firewall rules needed: https://stackoverflow.com/questions/26659223/appropriate-iptables-rules-for-an-ftp-server-in-active-passive-mode
Setting up your FTP users and permissions
This article goes fairly in depth on how to configure permissions and vsftpd settings: https://www.tecmint.com/install-ftp-server-in-centos-7/