Hansang Bae wrote:
>
> "Al" <[log in to unmask]> writes:
> >We just installed a series of Cisco Switches. The Show Command on
> >the switches usually gives you a good picture of what is going on
> >on that port.

> >BTW. I wonder if you could share your experience with us on these
> >switches.

We have a mix of Cisco Catalyst 2926s, 5000s, and 5500 in the university
hub, and 2924XLs and 1924XLs in the wiring closets.
Works great, lasts a long time :-)

> >We have 2 HP3K 928 with 10M NIC and three DTCs and BNC connectors
> >all sharing a Thin Ethernet and  conntected to HUB and then into a
> >port in one of our Cisco Switches.

If you're saying all are one coax segment, connected with BNC plugs,
then hooked to a switch port via a transceiver, you're fine.  If you
have other transceivers, be sure SQE is enabled on the DTC and 3000
sides, and disabled on the switch side.

:LINKCONTROL @;STATUS=D will give you error rates.  If you have
heartbeat losses, you have an SQE mismatch.

> >Some of our users connect via serial link, DTC to the 3Ks and
> >others connect using Reflection. Those using Reflection keep
> >getting disconnected. Those using serial link are not affected.
> >We have monitored the Cisco port that is connected the 3Ks HUB and
> >there are massive collisions all the time on this port. All
> >Reflection users are set at 10M still people getting disconnected.

If the switch ports are 10/100 half/full duplex auto-sensing, be sure
that everybody agrees on duplex.  The 10K ports on the DTC and 3000 will
all be 10Mb/half-duplex.  Your switch ports may not agree, and
if the Reflection users are on the switch, they must match as well.
If you have a duplex mismatch, you will usually see collisions (in
particular, 'late collisions') on the half-duplex side, and runts
and checksum errors on the full-duplex side.  You can set force speed
and duplex on the switch.

> >We have been advised by Cisco Engineer that we must get rid of the
> >Thin Ethernet and connect the 3Ks and DTCs directly to the
> >Switches.

That's one option, and will segment your collision domain.  It is a bit
of overkill unless you have a bad connector which you could possibly
find by process of elimination removing devices one at a time from the
network.

Jeff Kell <[log in to unmask]>