SUMMARY: Spray reporting 53% packet loss...

From: Sanborn, Ed (
Date: Mon Mar 08 1999 - 13:18:12 CST

Thanks. The only thing about this is that two other Sun's sitting nearby
report no packet loss. The system that drops packets has been causing me
headaches. Strange network thing's had been happening. In between sending
out the email minutes ago till now I finally narrowed
down the problem to be a network monitoring package called
Network Flight Recorder to be the culprit. When it's daemon's were
running I received the packet loss. I killed the deamon's for NFR and...
bingo...the problem disappeared. I repeated this a few times enough to
satisfy me. I remember now that the makers of NFR reported issues with
Solaris' network drivers and they reported significant packet loss. But
I thought they meant I'd loose packets as being monitored by NFR not real
packets meant for the machine :^( Oh well. I guess I'll move NFR to
a BSDI box like they suggest.


-----Original Message-----
From: []
Sent: Monday, March 08, 1999 2:19 PM
To: 'Sanborn, Ed'
Subject: RE: Spray reporting 53% packet loss...

Your network _will_ go black when you're spraying; spray is intended to
saturate your network to test responsiveness.

And actually, 47% of your total ICMP packets received on a network with any
kind of traffic on it is fairly OK; remember that ICMP is the lowest
priority IP traffic, and any other traffic on the network will step on it,
causing packet loss.

Spray is not intended to be an end-all-be-all network monitoring tool; it
will tell you, with some kind of regular usage and knowledge of how _your_
network functions, whether there is a problem somewhere.


Mark Neill, UNIX Systems Administrator
First American National Bank
Voice (615) 835-6489
Fax (615) 781-7895

-----Original Message-----
[]On Behalf Of
Sanborn, Ed
Sent: Monday, March 08, 1999 12:28 PM
To: Sun Managers (E-mail)
Subject: Spray reporting 53% packet loss...

<esanborn@bayonet:/usr/users/esanborn>spray brigade
sending 1162 packets of length 86 to brigade ...
        625 packets (53.787%) dropped by brigade
        11536 packets/sec, 992179 bytes/sec

I checked cabling. Spray'ing to another system nearby on
same switched hub not reporting any packet loss. Brigade
is running Solaris 2.6. It is an E450 with alot loaded and
running. Anything else I can check on? Running the SE tool
shows that the network goes "black" when spray'ing...


Ed Sanborn (978) 691-6496
Northchurch Communications Inc.
5 Corporate Drive
Andover, MA. 01810 Fax (978) 691-6300

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