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From: phil@brahms.amd.com (Phil Ngai)
Newsgroups: comp.dcom.lans
Subject: Re: Ethernet "heartbeat"
Message-ID: <1991May20.164813.23466@amd.com>
Date: 20 May 91 16:48:13 GMT
References: <12164@uwm.edu> <1991May16.004523.21301@berlioz.nsc.com> <104479@sgi.sgi.com> <1991May16.134857.1@ptavv.llnl.gov> <May.18.20.17.29.1991.13010@athos.rutgers.edu>
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hedrick@athos.rutgers.edu (Charles Hedrick) writes:

>be disabled by a configuration command.)  Newer cisco products use a
>cisco controller card, which can hear its own transmissions.  This
>allows a more complete test than what you get from heartbeat. But for

Hearing your own transmission only allows you to check your transmitted
data. It does nothing to exercise the collision signal path. Remember,
the AUI cable has three signal pairs, XMT, RCV, and SQE.

Also remember the last two letters of CSMA/CD.

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