Path: utzoo!attcan!utgpu!news-server.csri.toronto.edu!mailrus!ncar!boulder!daemon
From: hedrick@athos.rutgers.edu (Chuck Hedrick)
Newsgroups: comp.dcom.sys.cisco
Subject: Re: Interfaces statics don't jibe with Sniffer's
Message-ID: <25540@boulder.Colorado.EDU>
Date: 1 Sep 90 19:50:25 GMT
Sender: daemon@boulder.Colorado.EDU
Lines: 22

There is some ambiguity about what errors should be reported.  E.g.
do you report errors only in packets addressed to you, or in all
packets?  (If a packet is damaged, there may be no way to tell
reliably who it is addressed to.)  When there's a collision, there are
typically fragments of packets, which one could conceivable report as
runts, etc.  I believe the MCI's generally report everything they see,
and they're fast enough to see a lot.  Other vendors may have made
more conservative choices.  Generally it's not clear that these
differences in philosophy matter.  As long as a given interface works
consistently, you can tell when a net is degrading and needs work.  In
my opinion the higher error rates on MCI's are not a problem, and may
even be an advantage.

Apparently cisco has gotten enough flack about this that they are
going make changes to reduce the number of errors reported.  I'm a bit
worried about this.  I rely on the fact that I can look at error
counters on our cisco boxes to show the overall health of the network
attached to it.  This may no longer be true if cisco starts being
careful to report errors in packets only if they can be identified as
being addressed to the specific interface.  I'm hoping that if they
really do change, they'll provide me a configuration option to keep
getting the old behavior.