Interactive rlogin problem with nn

[Andrew H. Marrinson]

Hello,

I am having a very strange problem trying to use nn across an rlogin session
under Interactive Systems release 2.0.2.  I have nn version 6.4.9.

The problem is that whenever I run nn while logged in from another machine
via rlogin some output disappears.  The problem only occurs when both
client and server rlogin are ISC's.  The problem goes away when either
client or server (or both) are (e.g.) SCO ODT.  The problem also does
not occur with telnet (including ISC's).  It does seem to occur with
ISC's new 2.2 Unix (at least as a client).

The strange thing is it only happens with nn!  No other program does
this including rn, emacs, vi, etc.

Further investigation with a network analyzer shows that the missing
data is always the contents of a packet with the urgent pointer set.
The urgent pointer points to the last byte of the packet which contains
the value 03H.  I have looked at the latest rlogind source, and as far
as I can tell, this might happen when input and output are being flushed.

Unfortunately, I can't figure out where nn might be doing this.  A quick
check of term.c shows an ioctl to flush the input, but a quick test program
that does that doesn't reproduce the behavior.

At this point I am not so much looking for a fix, I'd be happy to find
someone who has had similar problems with nn or another program.  Also,
anyone who has any idea under what circumstances ISC's rlogind would
send OOB data as described above would be helpful.  The rlogind source
I have is almost certainly newer than what ISC based their port on, so
it only gives me an idea of what might be happening.

This is a real drag.  Any help at all would be appreciated.  Thanks in
advance.
--
		Andrew H. Marrinson
		Icom Systems, Inc.
		Wheeling, IL, USA
		(andy at icom.icom.com)