FTP 125 Data Connection Open vs 227 Entering Passive Mode
FTP 125 (Data Connection Open) is a 1xx Positive Preliminary response, while 227 (Entering Passive Mode) is a 2xx Positive Completion response. 125 indicates that the data connection is already open and the transfer is beginning. No need to open a new data connection. In contrast, 227 means that 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).
คำอธิบาย
The data connection is already open and the transfer is beginning. No need to open a new data connection.
เมื่อคุณพบเห็น
When the server reuses an existing data connection for a file transfer instead of opening a new one.
วิธีแก้ไข
No fix needed — the transfer is starting immediately. Your client should begin reading or writing data on the existing connection.
คำอธิบาย
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).
เมื่อคุณพบเห็น
After issuing the PASV command. The server switches to passive mode and tells the client where to connect for data transfer.
วิธีแก้ไข
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.
ความแตกต่างหลัก
125 is a 1xx Positive Preliminary response, while 227 is a 2xx Positive Completion response.
FTP 125: The data connection is already open and the transfer is beginning. No need to open a new data connection.
FTP 227: 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).
You encounter 125 when when the server reuses an existing data connection for a file transfer instead of opening a new one.
You encounter 227 when after issuing the PASV command. The server switches to passive mode and tells the client where to connect for data transfer.
ควรใช้อันไหนเมื่อไร
For 125 (Data Connection Open): No fix needed — the transfer is starting immediately. Your client should begin reading or writing data on the existing connection. For 227 (Entering Passive Mode): 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.