Age-old ethernet equipment

From: Pete Turnbull <>
Date: Thu Mar 29 16:49:12 2001

On Mar 29, 15:40, Iggy Drougge wrote:
> Pete Turnbull skrev:
> >On Mar 29, 6:39, Iggy Drougge wrote:

> >Well, they would really all be the same network -- they'd be all one
> >collision domain (any packet or collision appearing on one port would be
> >seen on all the others. That's what a repeater does).
> True, but at least they will look like that and there won't be a dozen
> unused ports.

Yes, I see what you mean. You won't get any more bandwidth on any part of
the net, nor on the whole net, but you will have the advantage that it's
easier to isolate a fault if one occurs. And of course, extra
blinkenlights, which is always A Good Thing :-)

> >> What management would be involved with a repeater?
> >Partitioning segments [...] Monitoring traffic levels [or] types
> >[...] Keeping a list of MAC addresses [...] setting [IP address]
> > or telling [the repeater] to use bootp/dhcp) or upgrade
> >the firmware, or set passwords.
> That monitoring seems interesting.

If you think so, find out about SNMP (Simple Network Management Protocol)
and possibly RMON.

If you have Windows, look for the SNMP service which is buried in one of
the subdirectories on your CD; it includes "snmputil" which you can use to
retrieve or set information (but beware if you install it on an
Internet-accessible machine as it makes a lot of things available to remote
enquirers and has a lot of security problems).

If you have Linux, look on the net for UCD SNMP (which has some command
line utilities) and SNMPY or SCOTTY. There's also gxsnmp but it's only in
an early stage of development.

For a bit of fun, take a look at Netcool (expensive!) or MRTG (free!).
 There's lots more, but that'll give you some idea. is a reasonable place to

> >> IOW it's just a glorified OFF switch. =)
> >Partitioning, is, yes. Segmenting isn't, it's just a way of making one
> >big(ish) hub do the job of a few smaller ones.
> I was rather hoping it had that ability.

Segementing? Not many repeaters do, especially old ones, as it needs a
fair amount of extra electronics. Basically it's done by a crossbar
switch, which is inside one large ASIC in modern repeaters that provide it.

The most common form of segmenting in hubs is in dual-speed (10/100baseT)
hubs; what they really do is segment the ports into a 10baseT segment and a
100baseT segement, with a little store-and-forward switch in between.

Pete						Peter Turnbull
						Network Manager
						Dept. of Computer Science
						University of York
Received on Thu Mar 29 2001 - 16:49:12 BST

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