FTP Error 110: Restart Marker Reply
FTP reply code 110 is a preliminary response sent by the server during a file transfer restart. It includes a marker that the client can use to resume a transfer from a specific byte offset rather than starting over. This is part of the REST (restart) mechanism defined in RFC 959. The marker format is server-dependent but typically contains a byte offset. This code is relatively rare in modern FTP usage since most clients handle resume operations through the REST command followed by RETR or STOR, receiving the marker information through other means.
Status
110 Restart Marker ReplyExample
220 ftp.example.com FTP server ready
USER alice
331 Password required for alice
PASS ****
230 User alice logged in
REST 524288
350 Restarting at 524288. Send STORE or RETRIEVE.
RETR backup.tar.gz
110 110 Restart marker replyHow to Troubleshoot
Verify restart support
Check that both the FTP client and server support the REST command for transfer resumption. Send FEAT to see if REST is listed in the server's feature set.
curl -v ftp://ftp.example.com/ -Q 'FEAT'
Use REST before RETR or STOR
To resume a transfer, send REST with the byte offset before issuing RETR (download) or STOR (upload). The server will acknowledge with 350 and then begin the transfer from the specified offset.
curl -C - -O ftp://ftp.example.com/largefile.zip
Check FTP connectivity
If transfers are frequently interrupting, verify that your network path to the FTP server is stable and that no firewalls are prematurely closing idle data connections.
Scan PortsCommon Causes
Transfer restart after interruption
highA previous file transfer was interrupted (network failure, timeout, or client disconnect) and the client is now resuming the transfer. The server sends 110 with a marker indicating the byte offset where the transfer can resume.
Server-initiated checkpoint during large transfer
mediumSome FTP server implementations send periodic restart markers during very large file transfers. These markers allow the client to resume from the last checkpoint if the transfer fails partway through.
Quick Diagnostics
Related Error Codes
Data Connection Already Open, Transfer Starting
The data connection is already established and the file transfer is beginning immediately.
File Status Okay, About to Open Data Connection
The server is ready to transfer the file and is about to open the data connection.
Closing Data Connection, Transfer Complete
The file transfer completed successfully and the data connection is being closed.
Connection Closed, Transfer Aborted
The data connection was closed unexpectedly and the file transfer was aborted.
References
| Specification | Section |
|---|---|
| RFC 959 | RFC 959 §4.2 |
Frequently Asked Questions
This reference was compiled from official RFCs, protocol specifications, and hands-on troubleshooting experience. AI tools were used primarily for formatting and organizing the content on the page.