221
FTP
221 Closing Control Connection
Service closing control connection. The server is logging out and closing the session in response to a QUIT command.
Quand vous voyez ce code
After issuing the QUIT command to gracefully disconnect from the FTP server.
Comment résoudre
No fix needed — the session has ended normally. Reconnect with a new session if needed.
Spécification
Comparer avec
Guides
FTP Reply Codes: Understanding File Transfer Responses
DNS & Networking
TCP Three-Way Handshake and Connection Lifecycle
DNS & Networking
Essential Network Debugging Tools: ping, traceroute, mtr, and tcpdump
DNS & Networking
RFC 959: FTP Protocol Deep Dive
Protocol Deep Dives
TLS 1.3: Faster, Simpler, More Secure
Protocol Deep Dives
Migrating from FTP to SFTP: A Complete Transition Guide
Migration & Upgrades
HTTP Access Log Management: Rotation, Parsing, and Analysis
Production Infrastructure
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