FTP 120 Service Ready Soon vs 503 Bad Sequence
FTP 120 (Service Ready Soon) is a 1xx Positive Preliminary response, while 503 (Bad Sequence) is a 5xx Permanent Negative response. 120 indicates that the service will be ready in a certain number of minutes. The server is not yet available but expects to be shortly. In contrast, 503 means that bad sequence of commands. The command is valid but was sent in the wrong order relative to other commands.
Description
The service will be ready in a certain number of minutes. The server is not yet available but expects to be shortly.
When You See It
When connecting to an FTP server that is starting up or temporarily busy with maintenance tasks.
How to Fix
Wait the indicated number of minutes and try connecting again. If the server never becomes ready, contact the server administrator.
Description
Bad sequence of commands. The command is valid but was sent in the wrong order relative to other commands.
When You See It
When you skip a required step, like sending PASS before USER, or RNTO without first sending RNFR.
How to Fix
Follow the correct command sequence. Common sequences: USER then PASS for login, RNFR then RNTO for rename, PASV then RETR for transfer.
Key Differences
120 is a 1xx Positive Preliminary response, while 503 is a 5xx Permanent Negative response.
FTP 120: The service will be ready in a certain number of minutes. The server is not yet available but expects to be shortly.
FTP 503: Bad sequence of commands. The command is valid but was sent in the wrong order relative to other commands.
You encounter 120 when when connecting to an FTP server that is starting up or temporarily busy with maintenance tasks.
You encounter 503 when when you skip a required step, like sending PASS before USER, or RNTO without first sending RNFR.
When to Use Which
For 120 (Service Ready Soon): Wait the indicated number of minutes and try connecting again. If the server never becomes ready, contact the server administrator. For 503 (Bad Sequence): Follow the correct command sequence. Common sequences: USER then PASS for login, RNFR then RNTO for rename, PASV then RETR for transfer.