Subject: Differences between -t & -T in binary ftpd line

From: Magdalena Hewryk <[email-masked]>
Date: Wed, 26 May 1999 17:54:25 -0400

Hi,
I'd like to set up timeout period for users.  Some of them are complaining
that they have been cut off in the middle of the d/l sessions.

My binary ftpd looks like this:
ftp     stream  tcp     nowait  root    /usr/sbin/in.ftpd       in.ftpd -L
-a

----Does -t option means timeout of an inactive session only?
----Does -T means logout form FTP session, no matter if the user is in the
process of d/l or u/l a file?

----Does my setting means that if user don't use FTP session, she/he will be
logged off in 15 min, and all my users have limited FTP session to only 2
hours?

Please advise,
Regards,
...Magda

$man ftpd
The ftp server will timeout an  inactive  session  after  15
     minutes.   If  the   - t option is specified, the inactivity
     timeout period will be set to timeout seconds.  A client may
     also  request a different timeout period; the maximum period
     allowed may be set to timeout seconds with the  - T  option.
     The default limit is 2 hours.

---

From: Gregory A Lundberg <[email-masked]>
Date: Wed, 26 May 1999 22:44:22 -0400 (EDT)

On Wed, 26 May 1999, Magdalena Hewryk wrote:

> I'd like to set up timeout period for users.  Some of them are
> complaining that they have been cut off in the middle of the d/l
> sessions.
> 
> ftp stream tcp nowait root /usr/sbin/in.ftpd in.ftpd -L -a
> 

Yes.

> ----Does -T means logout form FTP session, no matter if the user is in
> the process of d/l or u/l a file?

No.  It means the user cannot change their timeout (SITE IDLE command) to
anything larger that this value.

> ----Does my setting means that if user don't use FTP session, she/he
> will be logged off in 15 min, and all my users have limited FTP
> session to only 2 hours?

I use the following on the command line:
  -t 300 -T 300
which means: idle (inactivity) timeout, between commands, of 5 minutes.
The maximum idle timeout is also 5 minutes.  Users can change their idle
timeout to a lower value if they want.

I use the following in my ftpaccess file:
  limit-time anonymous 30
which means: anonymous users are allowed to be connected for a maximum of
30 minutes.  Transfers in progress at the end of that period will complete
as normal; the time limit is only for new commands being issued.

> The ftp server will timeout an inactive session after 15 minutes.  If
> the - t option is specified, the inactivity timeout period will be set
> to timeout seconds.  A client may also request a different timeout
> period; the maximum period allowed may be set to timeout seconds with
> the - T option.  The default limit is 2 hours.

Yes, this is what the defaults are.  Way too large, aren't they?

If you have users complaining that they are being timed-out in the midst
of a transfer, possible causes are:

 - Windows 9x/NT dial-up networking isn't seeing the FTP transfer as
   activity.  You'll need to have Microsoft rewrite the OS to fix this, or
   upgrade to a real system, like Linux or FreeBSD.

 - ISP terminal server isn't seeing the FTP transfer as activity.  Get
   another ISP.  One that knows what they're doing would be good.

 - Well, you know, this is the Internet and sometimes you just can't get
   there from here.  Routers fail.  Wires get cut.  Shit happens.  If it
   happens for long enough, you'll timeout the TCP socket and lose the
   transfer.  If it happens a lot, change ISPs.  Otherwise, give it a few
   hours (or a couple days) and see if it gets better.

 - "But they're local users!" .. look for a failing Ethernet card, hub or
   cable.

-- 

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