External access to home FTP server?

Question

VPN

What we have: a modem from a provider that distributes the Internet, an old computer. which now plays the role of a server on Ubuntu server 14.04, the Macbook on which I sit + I plan to buy a DNLA player.
Question: how can I get access from the Internet to the ftp server that is on the old computer? Can you tell me more about VPN how it can help here.

Answer 1

0. You need a "white IP", i.e. "not a gray wiki IP ". Simply put, the IP on the WAN port of the modem should not start with 192.168; ten; 172.16..172.31
Most providers provide a similar service (automatically or for a fee)
1. You need to find out if this address changes over time (usually - 1 time per day or when reconnecting). With a paid "white IP", it is usually permanent
2. It is necessary to assign an internal IP to the FTP server in your network behind a router. Either via DHCP binding or issuing statics (in this case, make sure that the statics do not overlap with the DHCP range) 3.
Use one of the following technologies
).
3.2 Use "smart FireWall" if your router has one
3.3 (recommended option) Configure in the FTP server a range of incoming connections for DATA connections and forward it on the router (usually called PortForwarding \ VirtualServer)
* FTP uses port 21 for "Control Channel" - control channel. To transfer data, FTP uses other data transfer ports (Data Channel), the range of which is set in the FTP server service settings. It is necessary to ensure that from outside 21 and the entire range of the Data channel was "bounced". It is also possible to use "passive FTP server mode", then this requirement must be met on the client.

Answer 2

port forwarding on the modem, provided that the provider issues a white address, and dyndns if it is dynamic