chaining hubs and switches

I read somewhere that fast ethernet (100 mbps) networks only allowed
for one hub between hosts, whereas with the older 10 mbps ethernet you
could have 3. Is there some rule like this for ethernet switches at
current network speeds? From reading, I would infer that they can
possibly be chained, since it appears that network segments can be
connected by switches, while all the segments can still be in one
subnet served by one router. What is the best way to connect up
multiple ethernet segments in one subnet? Thanks for any leads to
info on this.

Hello,

http://www.webopedia.com/TERM/5/5_4_3_rule.html


--
Cordialement,
Mathieu CHATEAU
http://lordoftheping.blogspot.com


<(E-Mail Removed)> wrote in message
news:(E-Mail Removed) oups.com...
>I read somewhere that fast ethernet (100 mbps) networks only allowed
> for one hub between hosts, whereas with the older 10 mbps ethernet you
> could have 3. Is there some rule like this for ethernet switches at
> current network speeds? From reading, I would infer that they can
> possibly be chained, since it appears that network segments can be
> connected by switches, while all the segments can still be in one
> subnet served by one router. What is the best way to connect up
> multiple ethernet segments in one subnet? Thanks for any leads to
> info on this.
>

Answer much appreciated, however, I am really trying to find out how
to best put together a segmented LAN using multiple switches on one
subnet. The 5-4-3 rule does not apply to this. Any further info
would be much appreciated. Thanks.

The hub limitation is about collision and the fact that everybody receive
every packet, so trunk between hubs are quickly full and hub generally got a
small backplane, so they can't manage too much packet at the same time.

Let's go away the 10M things, but everything in 100M full duplex.

Limitation is then the same between hub and switch, in the number between 2
hosts

The link i provided seemed a good answer, would you mind asking your
question a different way ?

--
Cordialement,
Mathieu CHATEAU
http://lordoftheping.blogspot.com


<(E-Mail Removed)> wrote in message
news:(E-Mail Removed) ups.com...
> Answer much appreciated, however, I am really trying to find out how
> to best put together a segmented LAN using multiple switches on one
> subnet. The 5-4-3 rule does not apply to this. Any further info
> would be much appreciated. Thanks.
>

Hi Runner,

There is no limitation in the number of hubs that can be on a segment, but
there is a practical limit of where the performance begins to dive. As you
pointed out, the guideline has always been no more than three and this still
holds.

Of course, switches are so cheap and most can handle span/ mirror ports so
there really isn't a use for them in a modern network. I would even argue
against workgroup switches outside of IT's control, but that isn't really a
fight for this forum.

I would seriously evaluate any plans you have to include hubs as you do
increase contention for network resources through collisions and you remove
any ability for full-duplex communication. You'll also note that 100-half
was not part of the original spec and was added later to support legacy
equipment. Though it is claimed to be supported, it simply doesn't perform
consistently.

Finally, the broadcast nature of hubs forces all attached devices to make
forwarding decisions and can lead to switch or server CPU utilization to
increase as they have to make decisions on each packet. This also opens you
up to security problems as the promiscuous nature of hubs make them an east
eavesdropping target.

With all of these problems, it hardly seems worth it.
--
Ryan Hanisco
MCSE, MCTS: SQL 2005, Project+
www.techsterity.com
Chicago, IL

Remember: Marking helpful answers helps everyone find the info they need
quickly.


"(E-Mail Removed)" wrote:

> I read somewhere that fast Ethernet (100 mbps) networks only allowed
> for one hub between hosts, whereas with the older 10 mbps Ethernet you
> could have 3. Is there some rule like this for Ethernet switches at
> current network speeds? From reading, I would infer that they can
> possibly be chained, since it appears that network segments can be
> connected by switches, while all the segments can still be in one
> subnet served by one router. What is the best way to connect up
> multiple Ethernet segments in one subnet? Thanks for any leads to
> info on this.
>
>

On Sep 16, 12:29 am, "Mathieu CHATEAU" <gollum...@free.fr> wrote:
> The hub limitation is about collision and the fact that everybody receive
> every packet, so trunk between hubs are quickly full and hub generally got a
> small backplane, so they can't manage too much packet at the same time.
>
> Let's go away the 10M things, but everything in 100M full duplex.
>
> Limitation is then the same between hub and switch, in the number between 2
> hosts
>
> The link i provided seemed a good answer, would you mind asking your
> question a different way ?
>
The article you referenced says that the 5-4-3 rule should not apply
to switched Ethernet networks. I am trying to find out how to build
large switched Ethernet networks.

Thanks, Ryan, for your reply. I posted the above before seeing your
reply. From what you say and what I have seen, I definitely agree
that hubs do not seem to be worth it for any sizeable network. I am
looking for instructions for building large switched networks.