On 22-Jul-98 Edmund A. Hintz spoke unto us all:
#  Hi,
#       Here's the deal. Apple Mac Quadra 700/20/230, NetBSD 1.3.2 standard 
#  install, addition of Apache 1.3b5. About once a day I get the following 
#  error message: "sn0:Recieve Overflow Buffer Exhausted", where "sn0" is my 
#  ethernet interface. Once this message arrives, the machine can still be 
#  pinged, or telneted to, but when trying to hit it from a web browser it 
#  times out. Only way I've found around it is to reboot. I've done a few 
#  searches on this error message, found nothing. Anybody got some ideas on 
#  what to look for? Thanks in advance for any information...
#  

This message means the little buffer on your ethernet card, or possibly the one
netbsd drains that buffer into, has filled up.  Usually this will be caused by
large amounts of traffic hitting a heavily loaded machine, and the various tcp
stacks can't drain the queue's fast enough.  You shouldn't have to reboot to
get things working again.. Most of the problem should be a whole ton of
connections in FIN_WAIT state in netstat.  Just stop incoming data to the
webserver for a few minutes (ipf would be useful for this) and shut down the
server... the queues should drain out.  

There might be a tweak somewhere you can set to increase the buffer size.. but
I would suggest that your machine is getting hammered, and maybe if its running
other stuff, to offload some of the work to another box.


---
Tim Rightnour    -  root@garbled.net
http://www.zynetwc.com/~garbled/garbled.html