227
FTP
227 Entering Passive Mode
Entering Passive Mode. The server provides an IP address and port number for the client to connect to for data transfer, formatted as (h1,h2,h3,h4,p1,p2).
Когда вы видите этот код
After issuing the PASV command. The server switches to passive mode and tells the client where to connect for data transfer.
Как исправить
No fix needed — parse the IP and port from the response to establish the data connection. If connections fail, check NAT/firewall rules on the passive port range.
Спецификация
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Руководства
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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