FTP Error

[Madhu_15]

Hi,

We are downloading a file from a FTP Server every day. This process runs successfully. But occasionally we receive a huge file (50MB, may be small for some people), on these occassions, after downloading full file the server gives an error "421 Service not available, remote server has closed connection". But we are able to receive full file successfully. Any idea why we are receiving this error message?

TIA,
Madhu

[Geoff Wild]

Hmnnn....sounds like the remote server has some sort of idle time out - and doesn't track the transfer as non-idle - as it doesn't close the connection during the transfer.

Basically - you transfer a small file, it complets within the "time out window", then you can go ahead an perform additional ftp commands/tranfers...but with the larger file, you don't complete within the window, so they punt your connection as soon as the transfer is complete.

Rgds...Geoff

[Steven E. Protter]

This is probably a timeout issue. It might also be the inetd daemon being restarted on th server. If you have responsibility for this system take a look at the following areas:

cron jobs that might disrupt the transfer
inetd.conf configuration
filesystem's getting full. A filesystem getting full might explain it.

If its a HP box, check /var/adm/syslog/syslog.log for messages coinciding with the message.

SEP

[Jan Sladky]

hi Madhu,
if it is possible, use the "hash" option before you start download, some ftp severs need it during download in order to forbid these kind of messages

br Jan

[Bharat Katkar]

Hi ,
Use "ndd" to set any tcp/udp related parameters. see man ndd.

# ndd -get /dev/tcp
list all tcp parameters and values.

# ndd -set /dev/tcp value

Just to add to the earlier responses those rightly explained the cuase.

Regards,

[Jeffrey Killian]

We used to have a similar problem with timeouts when transferring files (about the size you speak of) between servers. We were able to match te buffer window of the sending machine to match that of the target machine. That eliminated the timeout problem, and increased the transmission rate too!