Subject: Re: network hang
To: Jukka Marin , Wailer <>
From: Brain fried. Explanation is in file "core". <>
List: current-users
Date: 09/12/1997 21:45:20
AHA!  I'm NOT the only one!
Wailer sez:
 * > I'm using netbsd as a gateway/workstation.  P133/32 with scsi disks.
 * > I'm having an issue which I've seen off and on for a very long time
 * > in which the network just clogs up and ceases to move.  I run ppp over
 * > a v.34 modem attached to a 16550.  Lockups appear to occur with 
 * > heavy network use, but not always.  This last one happened while a
 * > client was running cu-seeme, so heavy udp use.

Jukka Marin sez:
/* So your PPP links locks up and starts working only after a modem disconnect
 * and redial?  I see this every now and then on all my NetBSD 1.2 boxes.  I
 * was hoping this problem had been solved by the com driver changes in
 * -current.  I thought there was a handshake problem in the com driver which
 * sometimes prevented data transmission.. but maybe it's not that, then.  I
 * haven't used an RS tester to see the state of the handshake signals but
 * I guess I should do that sometime.  My PPP link usually stays up for a few
 * days in a row, but on a 486 system we see the problem a few times a day.

I don't think it's com specific, though -- I'm using a SPARCstation IPX
[I've just been back and forth a little bit with this on port-sparc; no
further info just yet...] and I have the exact same problem!

I experience such anomalies as:

	'ftp get' works ok to a point (most of a large (1.3MB) file), and
	then kind of bellies up, eventually timing out with Connection reset.

	'ftp reget' gets about 12-13kB more and does the above.

Speed: 19200 (38400 gives "zs0a: fifo overrun"), USRobotics Sportster 28.8
with compression enabled; pppd with deflate 15/bsdcomp 15, no vj compression
(since that broke on me once).  Oh well.

 * The problem only affects one PPP link at a time, so I don't think it's
 * a generic networking problem (Ethernet always works just fine).
 *   -jm

No, but it's certainly not restricted to com*.

Humanocentric religions and ways of life have proven to be our undoing.