PBSZ FTP command

This article describes the use of the Protection Buffer Size (PBSZ) FTP command.

After completing the negotiation of a secure connection with the server, the client must issue the PBSZ command. This command sets the maximum size, in bytes, of the encoded data blocks to be sent or received during a file transfer. The provided parameter indicating the size requested by the client must be a 32-bit unsigned integer. If the server does not support the requested size and requires a smaller buffer, it must respond with an acceptable buffer size, which the client is required to use instead.

Common responses

• 200 FTP response code
• 421 FTP response code
• 500 FTP response code, 501 FTP response code, 503 FTP response code, 530 FTP response code

See also

AUTH FTP command