FTP cheatsheet

Service and ports

Check	Description
`systemctl status vsftpd`	vsftpd service status
`ss -tlnp \| grep :21`	Control port listening
`ss -tlnp \| grep vsftpd`	Passive data ports in use
`grep -v '^#' /etc/vsftpd/vsftpd.conf`	Active vsftpd settings

Interactive ftp client

ftp ftp.example.com
# login: user / password
ls
cd incoming
get remotefile.dat
put localfile.csv
binary          # for non-text files
passive         # PASV mode (default on many clients)
bye

lftp (scriptable)

lftp -u user,pass ftp.example.com -e "ls; get file.dat; bye"
lftp -u user sftp://host   # SFTP — encrypted alternative

# Mirror remote dir to local
lftp -c "open -u user,pass ftp://host; mirror /remote /local"

curl one-liners

Command	Description
`curl -u user:pass ftp://host/path/file.txt -O`	Download file
`curl -T local.csv ftp://host/incoming/ -u user:pass`	Upload file
`curl -v ftp://host/`	Verbose — debug PASV/ports

vsftpd — common settings

listen=YES
anonymous_enable=NO
local_enable=YES
write_enable=YES
chroot_local_user=YES
allow_writeable_chroot=YES
pasv_enable=YES
pasv_min_port=40000
pasv_max_port=40100
# Behind NAT — set public IP clients should use:
pasv_address=PUBLIC_IP

Firewall (passive range)

# Example: ufw allow 21, and passive range
ufw allow 21/tcp
ufw allow 40000:40100/tcp

# Test from client
curl -v ftp://user:pass@host/

Logs

Location	Description
`/var/log/vsftpd.log`	Transfers (if xferlog enabled)
`journalctl -u vsftpd -e`	systemd journal
`grep vsftpd /var/log/messages`	RHEL-style syslog

Secure alternatives (prefer these)

Protocol	Port	Notes
SFTP	22	SSH subsystem — SSH lab
FTPS	21 / 990	FTP + TLS
HTTPS / S3	443	Modern B2B APIs

Pro tips

Plain FTP leaks passwords — use VPN/private links or migrate to SFTP/FTPS
Directory listing hangs? Almost always passive ports or pasv_address
Chroot breaks if home dir is writable by the FTP user — check vsftpd docs
Finance partners often need fixed IPs, PASV range docs, and ASCII vs binary mode
curl -v shows the PASV IP:port the server advertises — verify it is reachable

Practice scenarios

Hands-on FTP scenarios on live Linux VMs: ftp