Subject: 426 Data connection: Broken pipe

From: "Rick Flood" <[email-masked]>
Date: Mon, 8 Feb 1999 13:15:43 -0500

I seem to be seeing a lot of these, '426 Data connection: Broken pipe', in
my ftplog.  I can generate one myself by stopping a transfer before it has
completed.  What other events can cause this message?

---

From: Gregory A Lundberg <[email-masked]>
Date: Mon, 8 Feb 1999 13:55:23 -0500 (EST)

On Mon, 8 Feb 1999, Rick Flood wrote:

> I seem to be seeing a lot of these, '426 Data connection: Broken
> pipe', in my ftplog.  I can generate one myself by stopping a transfer
> before it has completed.  What other events can cause this message?

Probably mostly people hitting 'Stop' on their web browser, or 'Cancel' on
the download.

426 occurs three places in the code:
 - in send_data() when a data error occurs
 - in receive_data() when a data error occurs
 - in myoob() when an ABOR command follows out-of-band data

This last cause replies to the client with
  426 Transfer aborted. Data connection closed.
  226 Abort successful
so it cannot be the case you're referring to.  At least in theory.  In
practice, I expect IE doesn't follow the protocol and simply closes the
connection in Microsoft's typical RFC-what-RFC? fashion.  So instead of
seeing this, the correct way to abort a transfer, we'll see one of the
other two causes.

Both send_data() and receive_data() call perror() for the error
description.  The description indicates that the ferror(), read() or
write() error returned errno set to EPIPE.  What specifically causes EPIPE
may vary from system to system.

Since it is pipe related, however, and since you're seeing a lot of it,
I'd suggest you have a lot of users hitting Stop while waiting for the
directory listing (output from ls, obtained through a pipe) to appear.

Other possible causes would be pressing Cancel while downloading file
processed through ftpconversion (sugh as .tar, .tar.gz) or pressing Stop
while waiting for a response from a SITE EXEC'd command.

-- 

Gregory A Lundberg		Senior Partner, VRnet Company
1441 Elmdale Drive              [email-masked]
Kettering, OH 45409-1615 USA    1-800-809-2195