Question & Answer
Question
FTP times out when transferring data to and from the z/OS FTP client.
Answer
FTP timeouts can occur during data transfer for the z/OS FTP client. Many times this results in the z/OS FTP server issuing messages EZA2590E and EDC8121I (connection reset), EZA2589e (connection interrupted or timed out), or EZA1721W (server not responding).
Be sure the following z/OS FTP client timer (specified in the client FTP.DATA file) default values are set to the defaults or higher:
CCONNTIME 30
DATACTTIME 120
DCONNTIME 120
INACTTIME 120
MYOPENTIME 60
PROGRESS 10
We usually see this type of problem occur when the DATACTTIME expires before all the data has been sent out. If this is the case, you may want to increase this value in the FTP.DATA file. This can be the DATACTTIME (default 120 seconds) specified in the FTP.DATA input (typically the SYSFTPD DD), or overridden with a TIMEOUT option when the FTP command is invoked. The rate of transfer must stay above 180KB for the specified period to avoid this kind of failure (>1.5KB/sec if using the default).
Issues can also arise when a firewall between the client and the server decides that the Control session is idle and sends a RST to close the control session before the data transfer is complete. For this situation we suggest coding a value for FTPKEEPALIVE in the FTP.DATA file 60 seconds or greater. With a short FTPKEEPALIVE time, a special packet is sent after the time interval, and some firewalls will not allow that, terminating the connection when the keepalive packet is detected. Some firewalls do not allow an idle connection to stay connected for more than a certain period of time. Check with your firewall support as to what the requirements to allow this to work.
If you have a checkpoint firewall, make sure you have turned off the FTP enforce new line setting in the firewall's configuration. Here are instructions on how to do this: Edit the $FWDIR/lib/base.def Change (comment out) the following line:
#define FTP_ENFORCE_NL to: //#define FTP_ENFORCE_NL
Re-install the security policy
Product Synonym
ZOSCS COMMSERVER
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Document Information
Modified date:
28 May 2015
UID
dwa1193530