Ports of some commonly used services. Unless otherwise specified the ports are tcp.

  • FTP uses 20(for data),21(for commands)
  • SSH uses 22
  • SMTP uses 25
  • HTTP uses 80
  • HTTPS uses 443
  • POP3 uses 110 1
  • IMAP uses 143 1
  • DNS uses 53 tcp/udp
  • NFS uses 2049
  • Samba uses 137, 138, 139
  • Squid uses 3128
  • Puppet Server uses 8140
  • TFTP uses 69 udp
  • Rsync uses 873
  • DHCP uses 67 udp(DHCP server), 68 UDP(DHCP client)
  • MySQL uses 3306

1 POP3 and IMAP are used by email clients to retrieve emails from server. The difference is that POP3 deletes the emails on the server after they have been retrieved by the client and IMAP keeps the emails on the server even after they have been retrieved.