225
FTP
225 Data Connection Open
Data connection open; no transfer in progress. The data channel is established and ready but no file transfer has started yet.
On this page
When You See This Code
When the data connection is established but idle, waiting for a transfer command to begin sending or receiving data.
How to Fix
No fix needed — the data connection is ready. Issue a RETR, STOR, or LIST command to start using it.
Specification
Compare With
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
Glossary
Status Code
TLS Handshake
TCP/IP
Three-Way Handshake
Port Number
Firewall
Proxy Server (Forward Proxy)
Socket
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RFC (Request for Comments)
Connection-Oriented
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Text vs Binary Protocol
FTP Active Mode
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FTP Data Channel
SFTP (SSH File Transfer Protocol)
FTPS (FTP Secure)
FTP Reply Code
FTP Anonymous Access
FTP Transfer Mode (ASCII vs Binary)
FTP Resume (REST Command)
SCP (Secure Copy Protocol)
FTP Chroot Jail
WebDAV (Web Distributed Authoring and Versioning)
rsync
FTP MLSD (Machine-Readable Listing)
FTP NAT Traversal
Transfer Integrity
FTP over TLS (RFC 4217)
File Locking
Bandwidth Throttling
TLS Versions
Frequently Asked Questions
What is FTP 225 Data Connection Open?
Data connection open; no transfer in progress. The data channel is established and ready but no file transfer has started yet.
When do you see FTP 225 Data Connection Open?
When the data connection is established but idle, waiting for a transfer command to begin sending or receiving data.
How to fix FTP 225 Data Connection Open?
No fix needed — the data connection is ready. Issue a RETR, STOR, or LIST command to start using it.