Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!zaphod.mps.ohio-state.edu!ncar!boulder!daemon
From: morris@windom.UCAR.EDU (Don Morris)
Newsgroups: comp.dcom.sys.cisco
Subject: cisco FDDI strangeness
Message-ID: <28971@boulder.Colorado.EDU>
Date: 31 Oct 90 00:08:40 GMT
Sender: daemon@boulder.Colorado.EDU
Lines: 21


We have a cisco AGS+ 8.1(21) with GS Software (GS2-F) that
has 2 FDDI boards.  We have this connected to an NSC FE649
box that also has 2 FDDI cards. (This is the start of an
FDDI test network we are setting up).

So, we have 2 separate FDDI rings to each box. Now when
we ping the cisco from the NSC on ring 1 we get a certain RTT.

If we diconnect ONE of the (two) optical cables from the cisco on ring 2,
the ping RTT increases by a factor of 2.
Disconnect both ring 2 cables and ping RTT increases a factor of 4.
In addition, "break" ring 1 by disconnecting one of cables and ping RTT
increases by factor of 6.

If we disable ring 2 in the cisco with the CMT command
"cmt discinnect fddi 0", the ping rate returns to normal.

Disconnecting the ring 2 cables on the NSC box has no effect.

Any ideas? Is this evidence of a bug and will it hurt anything?