SUMMARY - No-carrier error on Ethernet

From: Michael H. Morse (
Date: Wed Jan 22 1992 - 01:21:36 CST

My original question:`

> Does anyone know exactly what causes the error "No carrier" on an
> Ethernet? I replaced a Sun386i that was working fine with a Sparc 2
> running 4.1.1B, and I can't get the new machine to work on the
> Ethernet. It keeps saying "No carrier".

The answer from the net is that there is an actual "carrier" pin on the
transceiver cable, and the most likely cause for the error is a bad
cable, connector, or transceiver. In my case I took everything apart,
and put it back together using a different port on our multi-port
transceiver and it worked perfectly, and I didn't go any further to try
to locate the original proble.

Thanks to all that replied. I've included a few interesting comments

From: Dave <>
| Well, I assume the ethernet is actually working, so
| if you transceiver cable is ok, and so is your transceiver,
| check the ethernet fuse on the sparcstation... I'm not sure where
| it is on the SS2, but the SS1/1+ has it right by the ethernet
| port, on the motherboard...

and in the same vein...
From: Steve Swaney <steve@mapes>
| Have you tried checking the fuse on the eternet circuit. Its a small
| vertical cylnder with clear sided and a black top. There are 2 on the
| motherboard. One for the SCSI and one for the Ethernet.

From: Barry Shein <>
| Another remote (so to speak) possibility is that the ethernet device
| was not configured properly by ifconfig on boot. Do a:
| # /etc/ifconfig le0
| and see if the info printed out looks reasonable (do this before
| lugging the thing around, I'd suggest.)

A little info on "heartbeat". Since both my systems were Sun's I
figured they probably hadn't changed the heartbeat requirement, but
this info could be useful to someone:

From: "Scott E. Townsend" <>
| I can't say for sure (I don't have either flavor of Sun machine) but
| Ethernet tranceivers come in a few flavors. One flavor has a signal
| sometimes called 'heartbeat' which essentially tells the transmitter
| that the signal is indeed getting out to the wire. Some systems ignore
| this signal, some systems require it. The system I'm most familiar
| with would simply log 1 carrier loss per packet if you had a tranceiver
| which didn't give back a 'heartbeat'. Maybe 4.1.1B considers this a
| fatal error?

Thanks to:

Dave <>
"Pamela D. Hanes" <>
Brent Chivers <>
Kevin Sheehan {Consulting Poster Child} <kalli!>
fabrice cuq <>
Barry Shein <>
Ralph Merwin <>
Antonis Kyriazis <>
Steve Swaney <steve@mapes>
Mark Sims - Central Region Technology Manager <para1!detroit!>
Eckhard Rueggeberg <>
Marcel Bernards <>
Christian Candia White <synapsis!>
Lawson A S <>
"Scott E. Townsend" <>
Debbie McGlade <>

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