If your firewall blocks passive FTP, you might get an error message that reads: “Passive mode refused. Turning off passive mode. No control connection for command: No such file or directory.” If this happens, try using a "smart" FTP client like NCFTP (available on most UNIX machines). Smart FTP clients are better at auto-negotiating active/passive FTP connections than are older FTP clients (e.g., Sun Solaris FTP).

From: The Database of Short Genetic Variation (dbSNP)

Cover of The NCBI Handbook
The NCBI Handbook [Internet]. 2nd edition.
Bethesda (MD): National Center for Biotechnology Information (US); 2013-.

NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.