SUMMARY: ethernet receive failures

From: <jreed_at_appliedtheory.com>
Date: Tue, 05 Jun 2001 16:45:13 -0400

I asked about huge numbers of ethernet receive failures occurring
on 2 separate hosts, connected to same network:

       65535 receive failures, reasons include:
                Block check error
                Framing Error
                Frame too long

totaling up to 10% of traffic.

Joe Fletcher hit it when he suggested it could be the
"infamous duplex mismatch". I've posted here before
about duplex problems when trying to set our alphas
to 100/full (tulip interfaces).

These two particular hosts/interfaces were at 100/full,
but the 3-com switches were set to auto-negotiate,
and the switches were reporting that the alpha interfaces were
running at 100/half. When we hard set the 3-com interfaces
to 100/full, the errors stopped immediately!!!!!!!!!!!!

I'm not sure what the moral of this lesson is, other than
that you evidently can't trust and shouldn't use
"auto-negotiate" on 3-com switches.

Some other suggestions are appended below. Thanks to all
who replied!
 
Don Rye suggested:
        look for Novell clients on the network, sending
        incorrect frame types
Dr. Blinn suggested that something on the network was broken,
        such as a PC, flooding the wire with garbage. He noted
        that it would "break transmits (and lead to lots of
        retries) unless you've got full duplex networking and
        the transmit path is clean. If you have a half-duplex
        wire, then garbage will interrupt both transmits (via
        collisions) and receives."
John Francini suggested something on the net that was
        putting out packets that are too long - possibly
        a bad network interface somewhere - and suggested
        using a sniffer to locate the device.



-- 
Judith Reed
jreed_at_appliedtheory.com
(315) 453-2912 x5835
Received on Tue Jun 05 2001 - 20:46:24 NZST

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