I want to connect to my client's FTP. He has to whitelist my IP everytime since mine is dynamic. How do I connect to his server?
I would recommend you to rent a virtual private server (VPS) with static IP and use it as a jump machine to access your client's FTP server from a constant address.
He might use
Port Knocking. This way, it doesn't matter what IP you have, you'll "knock" to a sequence of ports and the Knock daemon will detect the sequence and therefore add a temporary rule to allow you to connect.
In Linux-based environments you can use
knockd for that matter, although I'm sure that for other OS environments there are equivalent daemons.
- Setup a free domain name.
- Use OpenDNS to keep the domain name associated with your IP.
- Have your friend whitelist your domain name.