This article is from the Frequently Asked Questions for Linux, the Free/Open Source UNIX-like operating system kernel that runs on many modern computer systems. Maintained by David C. Merrill with numerous contributions by others. (v1.0).
A: You can use the reget command of the standard ftp client program after reconnecting to pick up where you left off.
Clients like ncftp support resumed FTP downloads, and wget supports resumed FTP and HTTP downloads.