[12860] in Hotline Meeting
Red Light does not necessarily indicate a collision
daemon@ATHENA.MIT.EDU (Jeffrey I. Schiller)
Fri Jan 15 11:55:25 1993
Date: Fri, 15 Jan 93 09:06:48 EST
From: jis@MIT.EDU (Jeffrey I. Schiller)
To: jjmorey@Athena.MIT.EDU, vgeorge@MIT.EDU
Cc: kim@Athena.MIT.EDU, op@Athena.MIT.EDU, hotline@MIT.EDU, network@MIT.EDU
Reply-To: jis@MIT.EDU
> This is not a hardware problem but I don't know where else to send this report.
> Whenever I access our server (indus.mit.edu) it causes collisions on the
> network. This is obvious during source code compiles as evidenced by the red
> collision led on our transcievers. The workstations that generally access
> this server are indra, sita, brahma, karma, and arjun. The server is located
> in room E40-157. If you require access to the server, contact Varghese George
> in room E40-169 at 253-2430.
The red light on the transcievers do not always indicate a collision. The light
indicates both collision AND heartbeat. The heartbeat signal is sent by the
transceiver every time the connected host transmits.
In simple words: If the host is transmitting a lot (like it would during a
compilation) the red light should be on. If the red light is on when you *know*
that the host is *not* transmitting, then there is a problem. The way to know for
sure whether or not there is a network (or interface card) problem is to read out
the network statistics with the "netstat" command (caution, some number of
collisions are normal).
-Jeff
