Test FTP Access Remotely on CentOS

Linux Tutorials - Herong's Tutorial Examples

∟Test FTP Access Remotely on CentOS

This section provides a tutorial example on how to update firewall on the vsftpd server (and its firewall gateway if it is served in the cloud) to open ports 21 and 30000-31000 for inbound connections.

To allow users to upload and download files remotely, I need to open the firewall to allow users to upload and download files remotely using the vsftpd server on my CentOS computer.

1. Find the active zone of the firewall:

herong$ sudo firewall-cmd --get-active-zones

public
  interfaces: eno1

2. Add predefined "ftp" settings in the active zone "public" to receive incoming FTP connections.

herong$ sudo firewall-cmd --zone=public --add-service=ftp
success

3. Open a range of ports in the active zone to receive incoming FTP passive connections.

herong$ sudo firewall-cmd --zone=public --add-port=30000-31000/tcp
success

4. List all settings in the active zone "public":

herong$ sudo firewall-cmd --zone=public --list-all
public (active)
  target: default
  icmp-block-inversion: no
  interfaces: eno1
  sources:
  services: cockpit dhcpv6-client ftp http ssh
  ports: 80/tcp 3306/tcp 30000-31000/tcp
  protocols:
  masquerade: no
  forward-ports:
  source-ports:
  icmp-blocks:
  ...

5. Persist firewall changes to configuration files.

herong$ sudo firewall-cmd --runtime-to-permanent

6. Verify remote access by running an FTP client program on another computer on the same network, assuming that 192.168.1.3 is the IP address of vsftpd server computer.

herong$ ftp 192.168.1.3
Connected to 192.168.1.3.
220 (vsFTPd 3.0.3)
Name (192.168.1.3:herong): herong
331 Please specify the password.
Password:
230 Login successful.
Remote system type is UNIX.
Using binary mode to transfer files.

ftp> dir
229 Entering Extended Passive Mode (|||30445|)
150 Here comes the directory listing.
drwxr-xr-x    2 1000     1000           22 Jul 11 10:03 files
226 Directory send OK.

ftp> cd files
250 Directory successfully changed.

ftp> dir
229 Entering Extended Passive Mode (|||30768|)
150 Here comes the directory listing.
-rw-r--r--    1 1000     1000          637 Jul 11 10:03 test.txt
226 Directory send OK.

ftp> get test.txt
local: test.txt remote: test.txt
229 Entering Extended Passive Mode (|||30673|)
150 Opening BINARY mode data connection for test.txt (637 bytes).
100% |*********************************|   637    3.41 MiB/s    00:00 ETA
226 Transfer complete.
637 bytes received in 00:00 (1.08 MiB/s)

ftp> exit
221 Goodbye.

Very good. Remote FTP access is ready!

Note that if your server provided by an service provider in the cloud, you need open port 21 and 30000-31000 for inbound connections on the firewall gateway that protects your server.