13 replies
by avalon
SPEED!!!!!!!!!
A year ago I replaced my hubs with switches and we experienced a tremendous increase in network response time. I would never go back.
by rspeidel
by jdow
by noog
by greg roberts
by pkellett
by dharty
by pbenvenuti
by azhun
Repeater hubs just 'repeat' anything they hear to all points.
Switches learn the source addresses of devices attached to each port. They usually default to broadcast unknown destinations to all ports. They build a table of learned MAC addresses and so are pretty much protocol independant.
Switches are close to traditional bridges in their operation, but faster acting.
Cut through and store-n-forward are the two principle families of switching styles. In the first as soon as the destination header can be matched to a learned source address on a port the packet is 'cut' over to that port.
In store-n-forward the whole packet is stored and then path resolved. Cut throughs can pass packets whoes tails are mangled by collision and the collision. Store-n-forward would drop these. Store-n-forward takes longer for the packet to traverse out tof the switch.
Hybred partial store-n-forward switching methods where the first 128 bits or so are stored before cut through occurs is anattempt by some vendors to obtain the better attributes of both styles.
Basic Generalities
1. Hubs are repeaters that just repeat whats on the wire
2. Switches pass to all if unknown, but only to target port if learned.
3. Bridges store thenpass where learned destination and source addresses are located and usually pass if unknown
4. Routers store and then will forward only by the programmed rulles and drop unknowns.
So switch over hub - you betcha!
Managed switch if QOS and control is needed or in mature LAN with many iterations of growth over nummanged as it will better allow diagnostics on the wire and prevent accidental port misconfiguration with older devices.
Route where security or rulles need to apply and to provide greater isolation of faults like jabbers.
A switch and bridge can readily allow jabbers to takedown bridged/switched domains bounded by routed gateways.
IMHO
by doug.kapell
by 24-7
by chemlab1
by nichomach
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